These general conceptions of understanding and imagination correspond in a certain sense only to different points of view, under which we look at the mental functions, in themselves indivisible, and by means of which we separate them according to the relative, participation of their factors. So in the same way associations and combinations of apperception are not processes which belong to differing regions of our psychical life. On the contrary, not only are they always in a state of interaction, but apperceptions show that they arise out of associations, wherever we are able to trace them back to the conditions of their development. Nowhere can we see so clearly this rise of apperceptive combinations out of association as in spoken thought, the region of mental activity which is more than any other open to us in its objective forms. Let us explain this by means of an example, which is closely connected with the above examples of concrete and abstract forms of thought. We have taken the sentences out ofWilhelm Meister, which describe the coming of spring, as a sample of sensuous objective expression in the sense of forms of thought-construction familiar to us. And yet they are absolutely controlled by the laws of our abstract thinking, which join together widely separated elements of thought to one total idea in the interests of a unified combination, and compel us to use, in the form of particles and inflections, abstract elements of conception in order to arrange the parts of the scene described. This is different at a more primitive stage of thinking and expression in speech. Let us take, for example, the following simple statement in our own language: "He gave the children the slate-pencil." This sentence is for us directly concrete. If, however, we were to translate it just as it stands into the language of the inhabitants of the African colony Togo, they would probably not understand it. For such an individual even "slate-pencil" would be too abstract a conception. Further, he would not be able to imagine how any one could give something without having first of all taken it from somewhere else. The elements inserted between "slate-pencil" and the action of giving, which to us serve to combine the whole into one single idea, would mean to him rather a mixture of disparate elements. Lastly, he cannot form the concept "children" without thinking that they are children of some people or other. Accordingly our sentence would run somewhat as follows in the speech of the Togo negro: "He take stone to write something this gives of somebody child they." We must note here that even this literal translation still bears traces of the abstract culture of our language. The difference between substantives and verbs, which we have been forced to use, does not exist in the Togo language. If we look at such a sentence a little more closely, it is at once evident that the ideas are arranged exactly in the same order in which the objective process takes place. Each word denotes only one idea and is not placed in any grammatical category, since there are none such in this language. Therefore the expression of thought is still in essentials at the stage of pure association of ideas. Such a sentence only differentiates itself from a perfectly unsystematic association, that strays from one member to the other—as in the above-mentioned series, "school house garden &c."—by the fact that it follows directly the action described element for element, and therefore reproduces this in the memory exactly as it took place in perception.
Here we meet clearly the two motives which raise pure associations to apperceptive combinations by means of the impulses that lie in the association itself. One of these motives is an objective one. It lies in the regular concatenation of the outward phenomena which present themselves to our view, and which force the association to combine the ideas in the same regularity. A series, such as "school house garden &c.," is only possible when the thought process frees itself from perception and gives itself up to the incidental inner motives, which remain when the continuous succession of phenomena that regulates our thinking is wanting. Therefore association that is joined to these phenomena is in itself the more primitive, and in this way it is the regularity of the course of nature, which transfers its regularity to the normal association of our ideas. Added to this objective motive there is a second, a subjective one. We would not be able to hold together in association a series of impressions given to us in a certain order and to reproduce them again, were it not for our attention that follows from member to member the separate parts of the series, and ultimately binds them together into a whole. Thus ordered thinking arises out of the ordered course of nature in which man finds himself, and this thinking is from the beginning nothing more than the subjective reproduction of the regularity according to law of natural phenomena. On the other hand, this reproduction is only possible by means of the will that controls the concatenation of ideas. Thus human thought, like the human being himself, is at the same time the product of nature and a creation of his own mental life, which in the human will finds that unity which binds together the unbounded manifoldness of mental contents into one whole. In this way the development of apperceptive thought-combinations out of associations corroborates further the result obtained above in considering volitional processes, namely that to every outward voluntary action there correspond inner acts of volition which are occupied in influencing the course of thought. In the close combination between thought and speech this connection between inner and outer volition comes most clearly to light. We cannot act outwardly without at the same time executing inner acts of will. Therefore ordered expression of thought in speech corresponds as outward volitional activity to the control of the will over the associations that originally stray here and there without order. Even although thought in a primitive speech, as in the above example, may be ever so near to mere association of ideas, yet the control by the will is also to be seen in it, from the fact that the association series is one that inwardly is connected together. And with this we have the basis upon which the more complicated forms of apperception can rise, because of the continuous concentrations and combinations in thinking, and these latter at the same time find their adequate expression in the forms of speech. This connection between inner and outer volition, as we see it living in the connection between thought and speech, is ultimately of as great practical as theoretical importance. Only by considering this connection do we arrive at a sufficient understanding for the higher productions of human mental life. It also points forcibly to the fact that the most important part of education for the formation of character—i.e. the training of the will—should not only, and not even in the first instance, be directed to the outward act. Rather must education pay most attention to that inner volition which is occupied with ordered thinking. To make this strong, to make this able to resist the distracting play of associations, is its most important and also one of its most difficult tasks.
Many attempts have been made to investigate the processes of thought in other ways than in the way described above. At first it was thought that the surest way would be to take as a foundation for the psychological analysis of the thought-processes the laws of logical thinking, as they had been laid down from the time of Aristotle by the science of logic. Scholastic philosophy showed great subtlety in this direction in changing psychical processes into logical judgments and conclusions, and there are still followers of this direction at the present day. Starting with the thought-processes in the narrow meaning of the word, this logical explanation of everything psychical was allowed to spread over to associations, the processes of sense-perception, the pure sensations, feelings, emotions, &c., so that in this old scholastic psychology the human consciousness was in danger of becoming a scholastic philosopher, who regulated each of his actions according to the laws of logic. Now such laws are a late product of scientific thinking, which presupposes a long history of thinking determined by a number of specific factors. These norms, even for the fully-developed consciousness, only apply to a small part of the thought-processes. Any attempt to explain, out of these norms, thought in the psychological sense of the word can only lead to an entanglement of the real facts in a net of logical reflections. We can in fact say of such attempts, that measured by results they have been absolutely fruitless. They have disregarded the psychical processes themselves, and have gained nothing at all for the interpretation of the laws of logic simply because they saw in them the primitive facts of consciousness itself.
Many psychologists thought that this method could be improved by making use of direct introspection. They thought by turning their attention to their own consciousness to be able to explain what happened when we were thinking. Or they sought to attain the same end by asking another person a question, by means of which certain processes of thought would be excited, and then by questioning the person about the introspection he had made. It is obvious to the reader, who has followed our discussion so far, that nothing can be discovered in such experiments, where the most complicated psychical processes are investigated directly and without any further preparation. We need first of all a careful analysis of the more elementary psychical processes, of the facts of attention and of the wider scope of consciousness as well as of the relations between them and of the manifold affective processes that intervene in all these cases. Without having gained by these means the necessary information as to the general conditions and, so to say, as to the scene over which our thought-processes move, it is impossible in any way to understand these themselves in their psychical combinations. Many psychologists have connected this difficulty, not with the wrongness of their own method but with the essence of the thought-process. This was explained as an unconscious and (since all sense-perception belongs to consciousness) as a supersensual phenomenon, in the interpretation of which each one must be left to his own speculation. This opened the door at once to the explanation of psychical phenomena according to logical reflections, that were at will read into such phenomena. This alleged method of exact introspection ended ultimately at the point from whence it started, i.e. the scholastic philosophy.
In contradistinction to all this let us remember the rule, valid for psychology as well as for any other science, that we cannot understand the complex phenomena, before we have become familiar with the simple ones, which presuppose the former. Now the general phenomena of the course of simple processes in consciousness, as we have seen them in their most concrete form and under the simplest conditions in our observations of the combination and comparison of rows of beats, give us the most general preliminary conditions, which must be held as a criterion for much more complicated thought-processes. It is evident, however, that these formal conditions of all processes of consciousness cannot be sufficient to account for the special characteristics and phenomena of the development of thought. To do this we must turn our attention to this development itself, as it is shown in the documents of the spoken expression of thought at different stages of consciousness. It is unfortunate that in these and in other cases the development of the child, that is for us the easiest to observe, can give, as is obvious, only a few and in part only doubtful results. The speech and thought of the child, under the present conditions of culture, not only presuppose a number of inherited dispositions, whose influences can scarcely be accurately traced, but it is also absolutely impossible to withdraw the child from the influences to which, from the very beginning, its environment gives rise. Therefore the mental development of our children is under all circumstances not only an accelerated but also in many respects an essentially changed one, in comparison to a purely spontaneous development. On the other hand there are, at least in a relative manner, such stages of a spontaneous development of thinking, in many cases relatively independent of outward influences of culture, in the mental life of more primitive peoples. The different stages, which this mental life shows, find their most adequate expression in the outward phenomena of this mental life itself, and above all in those of speech, which is a means of expression and an instrument of thought at the same time. We can by means of the different stages of the development of speech follow that gradual transition of associative into apperceptive processes of consciousness from step to step. The example given above of a relatively primitive form of spoken thought shows the relation in which it stands to our languages of culture. A closer investigation of this subject would lead us beyond the scope of individual psychology into that of racial psychology, where the most important part deals with the psychological development of thought and speech.
Many psychologists and philosophers have denied the existence of special laws for our psychical life, if we understand this to mean specific laws, differing from the universal physical ones. Some say that everything that is called a psychical law is nothing but a psychological reflex of physical combinations, which is made up of sensations joined to certain central cerebral processes. Others maintain that there are no laws at all in the mental sphere. They say that the essential difference between natural and mental sciences consists in the fact that only the former can be reduced to definite laws, whereas the latter are absolutely wanting in any arrangement of phenomena according to law. The first of these opinions, that of materialistic psychology, can be passed over rapidly. It is contradicted by all the phenomena of consciousness that we have up till now discussed. It is contradicted by the fact of consciousness itself, which cannot possibly be derived from any physical qualities of material molecules or atoms. The indisputable affirmation, that there exist no processes of consciousness that are not in some manner or other connected with physical processes, is changed by this materialistic hypothesis into the dogma that the processes of consciousness themselves are in their real essence physical processes. Now this is an assertion that directly contradicts our immediate experience, which teaches us that a human being, or any other similar living creature, is a psycho-physical and not only a physical unity.
The second of the above opinions ascribes to the natural sciences alone laws in the sense of universally valid rules for phenomena, and therefore limits psychology in principle to the description of facts, which appear in their combinations to be arranged purely by chance or at will. This opinion rests obviously on a mistaken use of the conception of law. We are only allowed to consider those regularities in phenomena as according to law, which always repeat themselves in exactly the same manner. But there are in reality no such laws, not even in the natural sciences. For this principle is valid here: laws determine the course of phenomena only in so far as they are not annulled by other laws. Now because of the complex nature of all phenomena in general each process stands under the influence of many laws, and so it happens that just the most universal natural laws can never in experience be demonstrated in their full power. There is no law of dynamics which has a more universal validity than the so-called "law of inertia" or Newton's first law of motion. It can be formulated as follows: "A body in motion, and not acted on by any external force, will continue to move indefinitely in a straight line and with uniform velocity." It is obvious that this law can never and nowhere be realised in experience, since a case of independence from other external forces, which alter the motion, never and nowhere exists. And yet the law of inertia is for us an infallible law of nature, since all real processes of motion may be looked upon as lawful modifications of that ideal case (never existing in concrete experience) of a motion not acted upon by any external influences.
Let us now in the light of these considerations, universally acknowledged in natural science, consider the question of the existence or non-existence of psychical laws. It is of course self-evident that we may consider as laws only such regularities that lie within the process of consciousness, and not such as lie outside of consciousness, e.g. such as belong to physiological processes of the brain. Accordingly we may call combinations of sensations or of simple feelings into complex ideas, emotions, &c., psychical laws, if they in any way take place regularly. On the other hand, the fact that, if a bright point appears on a dark field of vision, the lines of vision of the two eyes are at once directed towards this point—this fact is a physiological and not a psychical law. Naturally such physical laws, as the one in our example, may have a determining influence upon the operation of certain psychical laws. But this does not hinder us from making a sharp distinction between the two kinds of law. We keep as a principle for a psychical law, that the components as well as the resultants of the effects of such laws are parts of immediate consciousness, i.e. sensations, feelings and their combinations. Now if we cast a glance, while keeping firmly to this criterion, over the manifold processes of consciousness, which have been touched upon in this book, we see at once that all these processes bear the character of a stem regularity. Not in the sense that these laws are fixed rules without exceptions (such laws as we have seen above do not exist, because of the never-failing interference from other influences), but in the only sense permissible, i.e. that each complex phenomenon can be reduced to a lawful co-operation of elements. If this requirement were not fulfilled, there would be no cohesion in our psychical life. It would break up into a chaos of unconnected elements, and consciousness itself, which is just the opposite of such a chaotic disarrangement, would be impossible. Therefore each separate idea is a combination of sensations according to law. A given clang of a definite timbre is put together unchangeably in the same way out of elementary tone-sensations. That certain objective sources of sound, e.g. strings, air spaces, possess physical qualities, by means of which such regular combinations of tone-quality arise, is undoubtedly a very important factor for the psychical law of the blending of tones. But these physical facts have in themselves nothing whatever to do with this law. If our consciousness was not disposed to such regular combinations, those objective factors would remain powerless. And it is exactly the same with the combination of light-sensations into spatial ideas, with the union of the images of an object in the right and left eye into one total image, with the rise of peculiar total feelings out of their partial feelings, as we have observed in the organic feeling and in the elementary æsthetic feelings, and last of all with the composition of the emotions and volitional processes out of their elements. Starting from these single more or less complex processes of consciousness, this character of regularity applies above all to the temporal succession of the processes. The generalisations of the old association psychology were absolutely inadequate, and its chief mistake lay, not so much in postulating laws too hastily, as in the fact that it did not attempt to penetrate deeply enough into the laws underlying the association processes by means of an analysis of the same. A last and conclusive testimony for this lawful character of psychical phenomena is given by the apperceptive combinations, whose specific products (of course quite dependent upon the laws of association), are the combinations of the thought-processes, as we have seen above. There can be no more striking proof of the absurdity of the above-mentioned theory of the lawlessness of psychical phenomena as the consequence to which it would lead us. For it would lead to the conclusion that the conception of law itself was contrary to law. This conception is in fact nothing more than one of the results of those psychical thought-combinations, the lawful nature of which is questioned.
It would lead us too far here to go into the profusion of psychical laws. The general character of them has been suggested in our chapters on association and apperception. In the natural sciences there are more general fundamental laws that rise above the separate particular laws, and these we may call the principles of investigation, in so far as they are general requirements to which investigation has to conform. In the same way we can set up fundamental laws in psychology which are not included in the separate regularities of phenomena, because they can only be gained from a general view of the whole of such phenomena. In physics, for example, the above-mentioned example of the law of inertia is a universally valid law. The same claim is raised in a wider scope by "the law of the indestructibility of matter," and by the near-related "principle of the conservation of energy." Are there, we naturally ask at once, psychological principles of similar universal validity?
Before we attempt to answer this question we must note one restriction, to which even in the natural sciences the requirement of universal validity for the leading principles is subject, and which, we may be sure, will be even more prominent in mental science, because of the extraordinarily complex nature of the phenomena. This restriction consists in the fact that the validity of each fundamental principle is subject to certain hypotheses, so that, where these are no longer fulfilled, the principles themselves become doubtful or untenable. Thus the law of the conservation of energy is only valid as long as the measured units of energy belong to a closed or finite material system. It loses its validity if the system is of infinite extent, or if, though finite, it can be acted upon by any external forces. A restriction analogous to this last one will have to be employed in regard to the psychical laws obtained by generalisation from the individual psychological regularities. Of course we must take into account the conditions arising out of the peculiarity of mental phenomena. These psychical laws, by virtue of the subjection of psychical phenomena to the interconnection of consciousness, can only be valid within the limits within which such an interconnection of psychical processes takes place. We shall, for example, try to obtain a fundamental principle which controls the formation of complex psychical processes out of their elements. But it would have no sense to set up such a law for absolutely disparate processes that do not stand in any relation in the single consciousness. It may be that, because of this, the limits of validity for psychological principles are much narrower than those for general natural laws. This is connected with the fact that psychology has to do with inner and not with outer relations. And also we must not forget that this limitation can be compensated for by the character of the psychical laws themselves. And, in fact, the discussion of the first and most general of these laws will show us that this hypothesis proves correct.
The first fundamental principle deals with the relation of the parts contained in a complex psychical process to the unified resultants into which they form. This relation can, as regards its qualitative content, be a most extraordinarily varying one, so that, in regard to the quality of the elements and their combinations, the separate psychical processes cannot be compared. Thus we cannot compare simple light sensations and qualities of tones, or a spatial visual image with a compound clang, or bring into comparison, according to their qualitative character, the relations of both of these pairs with those of the elements of an æsthetic feeling to that feeling itself, or with those of the separate feelings of an emotion to the total content of the same, or with those of the affective and ideational components of motives to the volitional process in which they take part. Nevertheless all these cases are regulated in regard to the formal relation between the components of a process and their resultants by one single principle, which we may call, for the sake of shortness, "the principle of creative resultants." It attempts to state the fact that in all psychical combinations the product is not a mere sum of the separate elements that compose such combinations, but that it represents a new creation. But at the same time, the general disposition of this product is formed by the elements, so that further components are not necessary for its creation, and indeed cannot be considered possible from the standpoint of a psychological interpretation. Thus in the light sensations of the retina, combined and fused with the sensations of strain in the eye in its movements and adjustments, are contained the essentials for the production of a given spatial image. At the same time this spatial image itself is something new, which as regards the resulting qualities is not contained in those elements. In the same way an act of volition that takes place under the influence of a number of motives, partly combating and partly aiding each other, is the necessary creation of this motivation, so that any specific process lying outside of these elements is nowhere to be observed. At the same time such an act of volition is no mere sum of motive-elements, but something new, that connects these elements into one united resultant. We see this creative and yet absolutely lawful nature of psychical phenomena best of all in apperceptive combinations, and for a long time it has been silently recognised in their case. Every one knows that the result of a chain of reasoning, made up of a row of single acts of thought, may be a product of those single thought-acts, which throws much light on some subject and which was before unknown to us, and yet which conclusively comes from those premises, if we analyse retrogressively its development. Upon this creative character of apperceptive combinations, above all, rests the regularity of psychical development, which is shown in the single consciousness during the individual life, and in the total mental development revealed to us by culture and history. The assertion that is occasionally made, based on dogmatic prejudices—namely, that the law of the constancy of matter, that is valid for the forces of nature, must necessarily keep mental life always at the same level in its total value—this assertion is contradicted by the facts of individual and universal development. That does not naturally exclude the possibility of individual interruptions of the course of development, and, because of these, of retrogressive movements arising, in consequence of the above-mentioned conditions, which govern all mental combinations. This combination of creative growth and strict regularity, which marks our mental life, is shown above all in the fact that, especially with the more complicated processes and the more extensive forms of progress of psychical phenomena, the future resultants can never be determined in advance; but that on the other hand it is possible, starting with the given resultants, to achieve, under favourable conditions, an exact deduction into the components. The psychologist, like the psychological historian, is a prophet with his eyes turned towards the past. He ought not only to be able to tell what has happened, but also what necessarily must have happened, according to the position of events. This point of view has in essentials for a long time been held in practice in the historical sciences. It must be of some value that psychology can show the same law of resultants even in the simplest sense-perceptions and affective-processes, where, in consequence of the simplicity of the conditions, very often the retrogressive deduction turns at the same time into a prophecy of events.
The law of resultants undergoes an important change in those cases, in which in the course of a psychical process secondary influences arise, which lie outside the region of the immediately produced resultants, and in which these secondary influences become independent conditions of new influences, which combine with those immediate resultants into a complex phenomenon. In such cases it may even happen that the secondary influences obtain the mastery and so degrade the original resultants to mere secondary influences or ultimately obliterate them altogether. Such a phenomenon may in longer processes be repeated several times and in this manner produce a chain of processes, the members of which diverge more and more from the starting-point of the row of phenomena. It is most of all processes made up of all other psychical compounds, i.e. volitional processes, in which this modification of the law of resultants may be demonstrated by means of numerous phenomena mostly belonging to racial psychology or the history of civilisation. An action arising from a given motive produces not only the ends latent in the motive, but also other, not directly purposed, influences. When these latter enter into consciousness and stir up feelings and impulses, they themselves become new motives, which either make the original act of volition more complicated, or they change it or substitute some other act for it. We may call this modification of the law of resultants, in accordance with the principal form in which it appears, "the principle of the heterogony of ends." It is of eminent importance for the development of the individual as well as of the general consciousness, and especially because the influences of original motives, that have decayed, are almost always preserved in some few traces alongside of the new ones that have taken their place. Such remnants of former purposes continue to exist in forms we do not understand in a great number of our habits, customs, and above all in religious ceremonies handed down to us from the past. Not only do these phenomena themselves remain obscure, but also the development of the present aims remains obscure, as long as we cannot account for them by the principle of heterogony that intervenes in all these cases.
As a supplement to the law of resultants, and yet at the same time in a certain sense as an expression for the same psychical regularity, we have "the law of conditioning relations." Just as the law of resultants joins into one unified expression the forms of psychical synthesis, so we may say that the law of relations is the analytic principle, which arranges under one general rule the relations of the components of one such synthetic whole. This rule consists in the fact that the psychical elements of a product stand in internal relations to each other, out of which the product itself necessarily arises, while at the same time the character of a new creation (a character that belongs to all psychical resultants) is caused by these relations. By inner relations we mean such as depend upon the qualitative constitution of the separate contents, and in so far stand, as a specifically different and at the same time complementary condition, in contradistinction to those external relations, which are determined by their formal arrangement. In this sense this distinction between external and internal relations corresponds to the difference in the ways of viewing the phenomena by the natural sciences and psychology respectively. The processes of nature are absolutely determined by the connection of temporal and spatial relations, in which the elements of the phenomena stand to each other. The mental processes on the other hand cannot, because of their subjection to natural phenomena, dispense with these external relations, but their inmost nature rests on the internal qualitative relations of the elements bound into one whole.
The law of relations stands in general reciprocal relationship to the law of resultants. Both of these laws apply to all compound unities of psychical phenomena, from the simplest ideational and complex affective processes up to the most complicated individual and general developments in psychical life. Thus the combination of a sum of tone elements into a single whole, by means of a specific ideational and affective value resulting from the combination itself, depends absolutely upon the qualitative and quantitative relations in which the tones stand to each other. This clearly arises from the natural dependence of resultants and relations upon each other, since each change of the latter modifies the constitution of the resultants in a corresponding manner. In the same way a spatial visual image is dependent on the relations of the qualitative and quantitative elements of the sensations of the retina and the strain sensations of the eye, and so on. A complex æsthetic feeling is a resultant of the simpler æsthetic feelings bound to the different parts of the perception, in so far as these latter again determine the product by means of their qualitative relations. And lastly all the processes of mental development are founded on the relations of their separate factors, by means of which they are combined into resultants. The interdependence of the laws of resultants and of relations shows us the importance of each of these principles. We cannot explain the psychical value of new creative compounds without considering the internal relations of their components, just as we cannot comprehend the peculiarity of these relations without continually taking into account their resulting influences.
Again in this case the most striking proof for the close connection between these two principles is given by the apperceptive combinations, especially in the forms of logical processes of thought, as they are expressed in the combination of sentences in speech. The thought-content of a sentence stands first of all, as we saw above, as a whole in our consciousness, but not yet as an ideational compound raised to clear apperception. In this stage it is a resultant from previous separate association and apperception processes. Then follows in the second stage of expression in speech, an analysis of that total idea into its parts, in which these parts are always put into close relations with each other. Such relations are called by grammarians subject and predicate, noun and adjective, verb and adverb, &c. The grammatical meaning of these categories shows clearly that this analysis consists of a system of primary and secondary relations, which are joined into a unified resultant by this logical arrangement. Thus the relation of subject and predicate includes all those further relations of noun and adjective, verb and object or adverb, as its minor terms, which are joined together partly by their own relations and partly by the relations of those most general members of the sentence, i.e. subject and predicate. This explains the psychological fact, that after this process of joining the thought together has passed, the total idea is once again, as at the beginning but this time more clearly, in consciousness. In a similar manner such single thought-compounds are combined into more extensive chains of thought, of which the relatively simplest forms are found in the process of drawing a conclusion.
The law of resultants finds a supplement and a specific application in the principle of the heterogony of ends in certain very important cases. In the same way we find, as supplementary to the law of relations, "the principle of intensifying contrasts." It includes those relations of psychical elements and compounds which are connected with certain limiting values of the qualitative and quantitative components of a whole. In the region of ideational combinations we have noted such influences of contrast in associative assimilations and dissimilations. We saw there that at a certain limiting value of the difference between two sensations or ideas, e.g. two spatial or temporal distances, two sound or light sensations, the assimilation present at a small difference may turn suddenly into a dissimilation. The impressions no longer assimilate, but become intensified through contrast. In another especially important form we meet the same principle in the feelings, where it stands in connection with the duality of the feelings that is valid for all affective processes and their combinations. In consequence of this each feeling, as we have seen, possesses its contrast-feeling, e.g. pleasure and displeasure, excitation and quiescence, strain and relaxation. Here the principle of relations shows itself in the form of the law of contrast, above all in the fact that the change between contrasting feelings itself intensifies the contrasts. Thus a feeling of pleasure is more intense, and its specific quality is more clearly felt, if it has been preceded by a feeling of displeasure. A similar relation exists between excitation and quiescence, strain and relaxation.
The law of contrasts is by no means limited to the relation between separate contents of consciousness existing side by side or following each other, but we see its most important influences in those places where it extends over more extensive groups of mental experience. Thoughtful historians have long since noted the fact, that in historical development not only do periods of rise and fall follow each other, but also periods of a special direction of mental life. And these periods, both in the impression they make upon us and in the objective relations in which they stand to each other, are so intensified that the following phase is every time increased by means of the contrast with the preceding one. Let us take an example from the near past. The German literature of the classicist period received its peculiar stamp of contemplative calm and beauty of form to a great degree from the contrast with the "storm and stress" period that was marked with such strong emotions. In the same way romanticism, which was inclined to the cult of the imagination and of a poetical past, was influenced by contrast with the preceding classical period, that laid most stress upon the understanding, and that regarded the present as the ripest fruit of human development. And lastly this change of contrasts shows itself most clearly and with the shortest oscillations in economic life, where it is in part assisted by the oscillations in the conditions of civilisation. We see this, for example, very well in the fluctuations of our national credit and of stocks and shares. And these sharp contrasts can be ultimately explained by the inner life of man that fluctuates between hope and hesitation, and in this fluctuation intensifies the emotions.
Let us now consider the connection of the four principles we have discussed. The second and fourth may be looked upon as special applications of the two fundamental principles of creative resultants and conditioning relations. We see also that they are not only joined very closely together, but that they stand, as absolutely disparate incomparable laws, in contradistinction to those general principles to which all natural phenomena are subjected. A contradiction has very often been thought to exist in the relation between the universal mental and natural laws. And since the natural laws are considered to be the more general and more necessary, these psychical principles have been looked upon as inadmissible generalisations, if they have not been absolutely ignored, which has more often been the case. Now we have seen in our whole discussion, that in reality we cannot move a step in the interpretation of psychical processes from the simplest sense-perceptions and affective combinations to the most complicated mental processes, as shown in society and history, without meeting with these principles always and everywhere. We must of course keep strictly to the maxim of analysing the psychical processes in their own connections and as processes joined together in themselves, as far as they so appear to us. Now the neglect of this maxim has led to the above-mentioned contradiction and to the disregard of these laws. In fact the reverse maxim has been formed, namely, that psychical processes should not be held as decisive for the principles that condition them, but rather that the laws of nature, founded upon external natural phenomena, should also rule our mental life. In this sense the law of the conservation of energy has been considered a fundamental law of all mental development. For this purpose, and also in order to preserve a kind of independence for our mental life, the conception of "psychical energy" has been formed. This, in all the changes it undergoes, is supposed to be subject to the law of the conservation of energy just like mechanical, thermal, electro-magnetic, or any other energy. Since we do not possess a definite unit of measurement for this psychical energy, and since it always occurs between two other physical energies, it was taken for granted that it could be indirectly measured. It could be placed in the middle of a series of transformations that took place according to constant equivalents as a value to be measured indirectly by the physical energy equivalent to it. For example, it could be placed between a given quantity of chemical energy, supplied from outside to the organism, and an equivalent quantity of warmth and mechanical work-energy, which the organism produces. If this were the case we could not reconcile with it a principle such as the one of creative resultants. Such a principle could not be included among the universal psychical laws; it would have to lie outside the general regularity of our psychical life. We can of course reverse this relation. Then we come to the result, that psychical regularity lies outside the law of energy, and in that case it would have no sense to place this psychical energy between two other physical energies and then attempt a measurement. Such a measurement is a pure fiction. We might just as well take any other fictitious process, say a miracle, and place it in the series of transformations.
These applications of physical laws to psychical phenomena are not based upon empirical facts, but they arise from a metaphysical principle, namely, the demand for a monistic view of life. Now this idea certainly has a justification, inasmuch as it rests upon a logical demand which it seeks to satisfy. If the so-called monism does not do this, it changes into a real dualism, as would clearly happen in the above-suggested rationalistic explanation of a miracle. In fact monism is only scientifically justified in its view of the relation between psychical and physical, as long as it emphasises the fact that the human being can just as little be considered a purely physical as a purely psychical being, and that man must be considered a psycho-physical individual, as we in reality experience him. This monism alone corresponds to the facts, A dualistic separation of soul and body, even if it sails under a monistic flag in the form of an atom-soul, or of an anonymous psychical energy, is a hypothesis which cannot be proved and which is useless for the interpretation of mental life. From the standpoint of the scientific and only justifiable monism, the mental processes are considered inseparable components of human and animal life. They must be judged according to the qualities that are immanent in them, and not according to laws which apply to other phenomena, and in the formulation of which no regard was paid to those psychical qualities. There cannot, however, be the least contradiction in the idea that physical and psychical phenomena follow different laws, as long as these laws are not irreconcilable with the actual unity of the psycho-physical individual. In reality we cannot talk of irreconcilability in this case, because firstly, the two series of phenomena are of a disparate nature, and because secondly everywhere, where these two series of phenomena meet together in the unity of the individual, they are really, as far as we know, subject to a principle of regular arrangement. Thus, for example, the law of creative resultants is not the least contradiction to the law of the conservation of energy, because the measures by which we determine psychical values cannot be compared with those with which we measure physical values. We judge the psychical according to its qualitative value, and the physical according to its quantitative value. The idea of value is in its origin really psychical, and this points to the fact that in reality physical values have in themselves no real measure, and that they only obtain one, if we make them the object of a comparative judgment, i.e. in a sense translate them into the psychological. Disparate values cannot in any way be compared, so long as a transformation of the one into the other is impossible. We can compare warmth and mechanical work, because the one can be transformed into the other according to a strict law of equivalence. But we cannot compare a tone with a sensation of light, or a visual idea with a chord, because a transformation of the one of these practical contents into the other is unthinkable. Now physical values are subject to the principle of the conservation of energy because of the unlimited capacity for transformation of physical energies according to equivalent relations. But it has on the other hand no sense to try to apply this same principle to the qualitative psychical values, which do not in any way admit of such a transformation. This of course stands in close relation with the fact that the subject-matter of psychology is the whole manifoldness of qualitative contents directly presented to our experience, each of which would immediately lose its own peculiar quality, if we tried to transform it into any other. Thus the physical phenomena investigated by the natural sciences and the laws of these phenomena do not in the least contradict the qualitative content of life dealt with by psychology. They rather supplement each other, inasmuch as we must combine them together into one whole, if we wish to understand the life of the psycho-physical being given to us in its unity.
Yet this impossibility of comparison of these qualities could not exist along with the unity of their substratum, if the physical and psychical values were not joined together in this substratum. This connection consists herein, that on the one side the physical elements, whether atoms or parts of one continuous matter, must necessarily be thought by us in forms of spatial and temporal ideas arising in accordance with psychical laws, and on the other side the psychical elements, the simple sensations and feelings, are inalienably bound up with definite physical processes. These latter need by no means be of a simple constitution, as has at times been presupposed by reason of metaphysical prejudices. The opposite is rather the case, as experience, which alone in this question can decide, incontestably teaches. For it shows that each simple sensation is joined to a very complicated combination of peripheral and central nerve-processes, and so also with the most elementary feeling, as is shown by the manifold "expression" phenomena which accompany the simplest feeling.
The actual correlation then is between simple, i.e. not further analysable, psychical content and complex physical processes. If, however, in contradiction to this, we introduce the metaphysical postulate of a correspondence between the psychically simple and the physically simple, we are inclined to go further and to presuppose a continuous correspondence between the two series of phenomena right up to the highest and most complicated content of consciousness. This regular relation between psychical elements and physical processes then becomes changed into a metaphysical parallelism, in which in content as well as in form the psychical becomes a copy of the physical, and the physical a copy of the psychical phenomenon. This hypothesis finds expression in the words of Spinoza, "The order and combination of ideas is the same as the order and combination of things." Such an idea was thinkable as long as the physical side of the qualities of living beings was so little known, and as long as there was no explanation of those psychological principles, which control the combination of processes of consciousness from simple sense-perceptions to complex thought-processes. At that Lime philosophy could take the liberty of building up reality out of abstract ideas, such as substance and causality. At the present day metaphysics, if it wishes to make any claim to respect, must build upon the real facts and not upon those ideas used from purely logical, dialectical motives. Even from this point of view there remains a "principle of psychological parallelism" in the sense that there is no psychical process, from the simplest sensation and affective elements to the most complex thought-processes, which does not run parallel with a physical process. Now sensation and affective elements cannot be compared in that way, since a simple process in the one case does not correspond to even a relatively simple one in the other, and this of course is valid for all other contents of consciousness formed from these elements. We meet everywhere physical and psychical as incomparable qualities of the united psycho-physical individual, and each of these must be judged according to the laws of combinations of elements, which are expressed in the combination itself. Since these qualities themselves are disparate, it can therefore never happen that the two principles come into antagonism with each other, whereas on the other hand, if we try to transfer the conditions that are only valid for the one side of the phenomena of life to the other side, we will very soon either come into antagonism with facts, or be forced to abandon an interpretation of a part of life placed in this manner under a strange point of view. Thus from the present-day psychological standpoint, which must be authoritative for a philosophical consideration, we can only speak of a "parallelism" between psychical and physical in as far as all elements of psychical life are joined to physical processes. The combinations of these elements, however, can never be judged according to the laws that are valid for the combination of the physical processes of life. If we try to do this, we eliminate what is most characteristic and important in our mental life. This reduction of the so-called principle of parallelism is occasionally called inconsequent and unsatisfying. This objection rests upon the interference ofa priorimetaphysical theories of the past, whose principles have long been thrown aside by science, and also upon ignorance of the real problem which psychology has to solve. This problem can surely never consist in applying, in connection with psychical processes, principles which do not belong to the psychical side of life. It must much rather consist in the attempt to gain principles out of the contents of our psychical life, just as in the reverse case physiological investigation of the change of matter and energy in the organism does not in the least, and rightly so, trouble itself with the psychical qualities of the organism. For the real unity of life will not be understood by subjecting real phenomena to laws with which they have absolutely no inner relationship. No, we must try to explain all sides of life and then the relations of these to each other.
From the standpoints which have here been developed as to the relation of psychical to natural laws and as to their combination into one unity, we may now decide a question which is of mythological origin, and which was transferred by mythology to philosophy and ultimately to psychology. This question is the one as to the nature of the soul. For the primitive thinker the soul was a demoniacal being, which had its seat in the whole body, but especially in certain favoured organs, such as the heart, the kidneys, the liver, or the blood. Besides this oldest idea of a body-soul, there soon arose a second idea of a soul only externally bound to the parts of the body, and this soul left the body at death in the last breath, and also for a short time during sleep, as noticed in the images of dreams. This was called the breath-soul or the shadow-soul. For a long time, in spite of the self-contradiction, these two conceptions were joined together, although we see in the development of mythological thought that the breath-soul or psyche slowly supersedes the idea of a body-soul.
The development of the idea of a soul in philosophy is in essentials a repetition of this mythological development. The ancient philosophy, in whose footsteps mediæval philosophy follows, still holds fast to the idea of a body-soul. The soul is the driving force of all, even physical processes of life, e.g. nutrition and propagation. By the side of this, however, the higher mental activities are bound to a specific being that is separable from the body. This opinion, which gave a concrete, clear form to the mythological ideas, found its most perfect scientific expression in the psychology of Aristotle. The psyche that was separable from the body had thus won a victory over the body-soul both in mythology and in the classical work of Aristotle. This, of course, led ultimately to the absolute dominion of this independent soul, and its qualities were more and more considered to be absolutely opposite to the qualities of the body, that was ruled by purely material laws. This development culminated in the system of Descartes, the last great philosopher of the Renaissance. The body is from now on considered to be an expended substance, subject to mechanical laws only; the soul stands, in contradistinction to this, as an unextended, purely thinking substance. The two substances are, however, during life externally joined together. In one single point of the brain the body was supposed to meet in reciprocal action with the soul, which was thought of as something analogous to a material atom. Descartes fixed upon the pineal gland, but there were countless other hypotheses as to the position of this point.
This is not the place to follow the further changes that these ideas underwent in the history of modern philosophy and psychology. All the later changes of the dualistic hypothesis are not of the first importance. The fundamental principle is, that the soul is a permanent substance, and the psychical processes are looked upon as changing phenomena of this substance, which are, however, different from it. This hypothesis may take the form that Spinoza gave it in presupposing the two substances changed into two attributes which run parallel with each other. There is also the materialistic hypothesis that reduces the soul-substance to a quality of the bodily substance, which alone is recognised as real. It becomes clear to us that such further developments of the "substance" hypothesis become more and more contradictory to the laws of psychical life, the more they attempt to explain the self-contradicting conception of two absolutely different substances which must be bound together into one unity. The Cartesian soul can no longer exist in face of our present-day physiological knowledge of the physical substratum of our mental life. And metaphysical monism in these two forms, which try to combine soul-and body-substance into one unity, would shut out the possibility of any knowledge of our psychical life.
Therefore, in contradistinction to this metaphysical concept of a mind-substance, we set up the concept of the actuality of mind. Mental processes are not transient appearances to which the soul stands in contradistinction as a permanent, unknowable being unrelated to them, so that any attempt to combine the two must necessarily lead to a tissue of influences and counter-influences, which were at will given the conventional names: "ideas, feeling, striving, &c." A striking example of the futility of such an attempt to make substance the basis of an explanation of mental life is seen in the last and most thorough-going of these theories, i.e. in Herbart's so-called Mechanism of Ideas. Certainly all psychical phenomena is a continual coming and going, a producing and being produced. But no supersensuous substance, standing in contradistinction to these phenomena, can help us to understand the latter in their separate parts, or even in the connection of these parts into a whole. Sense-perception is a product of elements of pure sensation, an emotion is the course of directly experienced feelings, a thought-process is a combination of its elements established by itself. Nowhere do these facts of real mental life need another substratum for their interpretation beyond the one that is given in the facts themselves. And the unity of this life does not gain in the least, if we add to its own real union another substance, which is neither perceived nor really experienced, but which stands as an abstract conception in contradistinction to that mental life established by itself.
We only need to cast a glance at the sciences most closely connected with psychology, i.e. the so-called mental sciences, in order to become aware of the emptiness and futility of this psychological conception of "substance." The name "mental science" has only the right to exist, so long as these departments of learning are based upon the facts of psychology—the mental science in the most general sense of the term. Now when would a historian, philologist, or jurist make use of any other means to understand some phenomenon or of any other arguments to prove some statement than those which spring from immediate facts of mental life? Why then should the standpoint of psychology be in absolute contradiction to the stand-points of its most nearly related sciences? Psychology must not only strive to become a useful basis for the other mental sciences, but it must also turn again and again to the historical sciences, in order to obtain an understanding for the more highly developed mental processes. Racial psychology is the clearest proof of this latter. It is one of the newest of the mental sciences and depends absolutely on these relations between psychology and the historical sciences. It is the first transition from psychology to the other mental sciences.
The metaphysical psychology of the present day, that has developed out of Descartes' theory of two substances absolutely different and yet externally joined together, this psychology seems unquestionably to be further away from the reality of the mental life than the theories of the ancient metaphysicians were. The old idea saw in the soul the principle of all life, or, according to Aristotle, the energy working towards an end, out of which the whole of the phenomena of life, physical and psychical, sprang. It sought at least to account for that unity of life, which popular dualism must regard as a wonder, if it does not suppose the psychical to be a confused image of the physical, or reversely suppose this latter to be a mere subjective idea without its own reality. And yet this old vitalistic idea of a soul is for us no longer possible. For it tries to explain the unity of life only by postulating an all-embracing idea of purpose or use in place of a causal explanation of phenomena such as is now demanded. This vague notion of purpose does not explain the peculiarity of mental processes, nor does it fulfil the requirements of a natural explanation in regard to the physical side of the phenomena of life. Nutrition, propagation, movement, on the one hand, and perception, imagination, understanding, on the other, cannot be combined into one unity, even although the facts which these concepts denote are purposeful from the standpoint of the connection of the phenomena of life. They do not resist such a combination because they are bound up with essentially different substrata, but because they depend upon absolutely different stand-points of the phenomena of life given to us as a unity. Nutrition, propagation, movement, are organic processes which belong to objective nature, and for which, because of their own characteristics, the ideas we form of them serve as signs which point to an existence independent of our consciousness. In investigating them, just as in the investigation of natural phenomena outside our own body, we must abstract from the subjective processes of consciousness, to which they are bound, if we wish to understand them in their objective natural connection. On the other hand our ideas, inasmuch as they are subjective, our feelings and our emotions are immediate experiences, which psychology tries to understand exactly in the way in which they arise, continue, and enter into relations with each other in consciousness. Therefore it is one and the same psycho-physical individual forming a unity, which physiology and psychology have as subject-matter. Each of these, however, views this subject-matter from a different stand-point. Physiology regards it as an object of external nature, belonging to the system of physical-chemical processes, of which organic life consists. Psychology regards it as the system of our experiences in consciousness. Now for every piece of knowledge two factors are necessary—the subject who knows and the object thought about, independent of this subject. The investigation of the subject in his characteristics, as revealed to us in human consciousness, forms therefore not only a necessary supplement to the investigations of natural science, but it also attains to a more universal importance, since all mental values and their development arise from immediately experienced processes of consciousness, and therefore can alone be understood by means of these processes. And this is exactly what we mean by the principle of the actuality of mind.