The organ of vision is the eye, which is one of the most curious and wonderful parts of the human frame, and displays in astonishing variety the wisdom and skill of its Designer.
The eye consists of a round ball, formed externally of various coverings, and within of humors of different degrees of consistency. The front part of the eye, which is exposed to view, has a small opening in it, which admits the rays of light within this ball, while it is by the operation of light on the nerves, which are spread in fine net-work over the interior, thatsightis produced.
In examining the mechanism of the eye, a great variety of contrivances appear, all aiding in accomplishing the object of vision. In the first place, we may observe its modes of protection and defense. The lid is a soft, moist wiper, which, with a motion quick as lightning, protects the eye from outward violence, cleanses it from dust, veils it from overpowering radiance, and in hours of repose entirely excludes the light. On its edge is the fringing lash, which intercepts floating matter that might otherwise intrude, while above is spread the eyebrow, which, like a thatch, obstructs the drops that heat or toil accumulate on the brow.
We next observe the organs of motion with which the eye is furnished, and which, with complicated strings and pulleys, can turn it every way at the will of the intelligent agent. Thepupiloropeningof the eye, also, is so constructed, with its minute and multiplied circular and crossing muscles, that it can contract or expandin size just in proportion as the light varies in intensity.
The ball of the eye is filled with three substances of different degrees of density. One is a watery humor, near the front of the eye; back of this, and suspended by two muscles, is the solid lens of the eye, or thecrystalline humor; and the remainder of the eye, in which this lens is imbedded, consists of thevitreous humor, which is of the consistence of jelly. These all have different degrees of transparency, and are so nicely adjusted that the rays of light, which start from every point in all bodies indiverginglines, are by these humors made toconvergeand meet in points on theretina, or the nerve of the eye, forming there a small picture, exactly of the same proportions, though not the same size, as the scene which is spread before the eye.
When the outer covering of the back part of the eye is removed, the objects which are in front of the eye may be discerned, delicately portrayed in all their perfect colors and proportions, on the retina which lines the interior. It is this impression of light on the optic nerve which gives our ideas of light and colors.
The eye is also formed in such a way that it can alter its shape and become somewhat oblong, while at the same time its lens is projected forward or drawn back. The object of this contrivance is to obtain an equally perfect picture of distant and of near objects.
Our ideas ofshapeandsizeat first are not gained by the eye, but by the sense of touch. After considerable experience we learn to determine shape and size by the eye. Experiments made upon persons bornblind and restored to sight furnish many curious facts to support this assertion.
When the eye first admits the light, all objects appear totouchthe eye, and are all a confused mass of different colors. But by continual observation, and by the aid of the sense of touch, objects gradually are separated from each other, and are then regarded as separate and distinct existences.
The eye is so formed that the picture of any object on the retina varies in size according to itsdistance. Two objects of equal size will make a different picture on the back of the eye, according to the distance at which they are held. The ideas of size at first are regulated by the proportions of this picture in the eye, until by experience it is found that this is an incorrect mode, and that it is necessary to judge of thedistanceof a body before we can determine itssize. This accounts for the fact that objects appear to us so different according as we conceive of their distance, and that we are often deceived in the size of bodies because we have no mode of determining their distance.
But it appears also that our ideas of distance are gained, not by the eye alone, but by the eye and the sense of feeling united. A child by the sense of feeling learns the size of his cup or his playthings. He sees them removed, and that their apparent size diminishes. They are returned to him, and he finds them unaltered in size. When attempting to recover them, he finds that when they look very small he is obliged to pass over a much greater distance to gain them than when they appear large, and that the distance is always in exact proportion to their apparentsize. In this way, by oft-repeated experiments, the infant reasoner learns to judge both of the size and distance of objects. From this it appears that, in determining the size of an object, we previously form some judgment of its distance, and likewise that, in finding the distance, we first determine the size.
Theshapeof objects is learned altogether by the sense offeeling. It has before been stated that at the first exercise of vision every thing is a confused mass of different colors, and all appearing to touch the eye. By the aid of the hands the separate existence of different bodies is detected, and the feeling of touch, which once was the sole mode of determining shape, is now associated with a certain form or picture on the eye, so that, in process of time, the eye becomes the principal judge of shape.
But, in determining the shape of a thing, an act of judgment is necessary. This may be illustrated by the example of a hoop, which in one position will make a picture in the eye which is circular, in another position the picture of it will be oval, and in another only a straight line. If a person will observe a hoop in these different positions, and then attempt to draw a picture of it, he will be conscious of this varying picture in the eye. Of course, in order to decide the shape of a thing, we must decide its distance, its relative position, and various circumstances which would alter the form of the picture in the eye. It is only by long experience that the infant child gradually acquires the power of determining the shape, size, and distance of objects.
The painter's art consists in laying on to canvas anenlarged picture of the scene which is painted in the interior of his own eye. In this minute picture of the eye, the more distant an object the smaller its size, the more indistinct its outline, and the fainter its colors. These same are transferred to canvas in an enlarged form; the distant objects are made small in size, faint in colors, and indistinct in outline, just in proportion to their distance.
The organ of vision is the inlet of more enjoyment to the mind than any of the other senses. Through this small loop-hole the spirit looks forth on the rich landscape of nature, and the charms both of the natural and moral world. The fresh colors, the beauty of motion, the grace of figures, the fitness of proportion, and all the charms of taste, are discovered through this medium. By the eye, also, we learn to read the speaking face of man, we greet the smile of friendship and love, and all those varying charms that glance across the human face divine. By the aid of this little organ, too, we climb not only the summits of earth's domains, but wander forth to planets, stars, and suns, traverse the vast ethereal expanse, and gather faint images and flitting visions of the spirit's future home.
Therehas been much speculation on the question as to whether the mind possesses any ideas entirely independent of the senses, which were gained without any aid or influence from them. Many have maintained the existence of some ideas, which they denominateinnate ideas, which they suppose were originally implanted in the mind, and not at all dependent on sensation.
On this subject it may be sufficient to remark that there is noproofof the existence of any such ideas. All ideas, so far as we can trace them, seem to have been originally gained by the senses, though the mind has the power of making new arrangements and combinations of such materials as are thus furnished.
The intuitive truths seem to exist as a part of the original constitution of the mind, but there is no evidence that they would ever have been called into exercise except through the instrumentality of the senses.
There is nothing to prove that the positive exercise of thought, feeling, and volition is necessary to the existence of mind, and no proof that the mind might not have existed forever without thought or feeling of any kind, were it not for the aid of the senses. We know that there are periods of sleep and of swooning, when the mind is in existence, and yet when there is no evidencethat either thoughts, feelings, or volitions are in exercise.
Speculations on this subject seem to be profitless, because there are no data for determining them. Thefactsin the case are not of a character to enable us to pronounce positively either that these operations are or are not essential to its existence. It may be that in sleep and in a swoon these phenomena exist, and no memory is retained of them, and it is equally probable that at such intervals all mental operations entirely cease.
But, now that the mind has been furnished by the senses with its splendid acquisitions, upon which its reflective powers can act, it is easy to believe that it might continue to exist and to be in active exercise if all its bodily senses, and even its material envelope, were destroyed. Should we never again behold the light of heaven, nor be charmed with the profusion of varied color and form, still the mind could busy itself with pleasing visions of brilliant dyes, of graceful outline, and fair proportion, as bright and as beautiful as any objects of sense could awaken. Should we never again inhale the freshness of morning or the perfumes of spring, the mind itself could furnish from its stores some treasured incense, never to be entirely exhaled. Should the palate never again be cooled by the freshening water of spring, or be refreshed by the viands of the luxuriant year, yet fancy could spread forth her golden fruits and sparkling juices in banquets as varied and profuse as ever greeted the most fastidious taste. Should the melodies of speech and of music be heard no more, and the sweet harmonies of natureand of art forever be hushed, yet the exulting spirit could warble its own songs, and melt in ecstasies with imagined harmonies. And should the grasp of friendship rejoice us no more, nor the embrace of affection send joy to the heart, yet still the spirit would not be desolate, for it could gather around it the beings most loved, and still feel the embraces of affection.
Conceptions are distinguished into two classes with reference to this one fact, that some of our conceptions are attended with a consciousness that they have existed before, and others are not. Those conceptions which are thus attended with the feeling of their resemblance to past perceptions or conceptions are called ideas ofmemory; those of ourperceptionsalso which are attended with this recognition are called memory.
How important to our happiness and improvement is this recognition of past ideas, few are wont to imagine. If all our knowledge of external things were forever lost to us after sensation is past, our existence would be one of mere sensitive enjoyment, and all the honor and dignity of mind would be destroyed. No past experience could be of any avail, nor could any act of judgment or of reasoning be performed. Even the most common wants of animal nature could not be supplied; for, were the cooling water and sustaining food presented to the sight, no memory of the past comfort secured by them would lead the mind to seek it again. Or, had nature, by some implanted instinct, provided for these necessities, yet life in this case would have consisted of a mere succession of sensations, without even the amount of intellect of which the lower animals give proof.
It is the capacity of retrospection, too, which gives us the power of foreseeing the future, and thus of looking both before and behind for sources of enjoyment in delightful reminiscences and joyful anticipations. It is this power of remembrance and foresight which raises man to be the image of his Creator, the miniature of Him who sees the end from the beginning, who looks back on never commencing ages, and forward through eternal years.
It is true the mind of man can foresee only by the process of reasoning, by which it is inferred that the future will, in given circumstances, resemble the past. And how the Eternal Mind can foresee by intuition all the events which hang upon the volitions of the myriads of acting minds which he has formed is what no human intellect can grasp. Theforesight of intuitionhas not been bestowed upon man, but is reserved as one distinctive prerogative of Deity.
Tounderstand clearly the nature of the mental phenomena calledattentionandabstraction, two facts in our mental history need definitely to be understood—facts which have a decided bearing on the nature and character of almost all the operations of mind.
The first is, that the objects of our conceptions are seldom, if ever, isolated, disconnected objects. On the contrary, there is an extended and complex picture before the mind, including often a great variety of objects, with their several qualities, relations, and changes. In this mental picture some objects are clear and distinct, while others seem to float along in shadowy vagueness.
This fact must be evident to any mind that will closely examine its own mental operations. It is also equally evident when we consider the mode in which our ideas are gained by perception. We never acquire our ideas in single disconnected lineaments. We are continually viewing complex objects with numerous qualities and surrounded by a great variety of circumstances, which unitedly form awholein one act of perception.
Indeed, there are few objects, either of perception or conception, which, however close the process of abstraction, do not remain complex in their nature. The simplest forms of matter arecombinedideas of extension,figure, color, and relation. These different ideas we gain by the aid of the different senses. Of course, our conceptions are combinations of different qualities in an object which the mind considers asone, and as distinct from other objects.
Each item, then, in any mental picture is itself a complex object, and each mental picture is formed by a combination of such complex objects. It will be found very difficult, if not impossible, to mention a name which recalls any object of sense in which the conception recalled by the word is a single disconnected thing, without any idea of place or any attendant circumstances, and, as before remarked, almost all objects of sense are complex objects, combining several ideas, which were gained through the instrumentality of different senses. The idea of color is gained by one sense, of position, shape, and consistency by another, and other qualities and powers which the mind associates with it by other senses.
The other fact necessary to the correct understanding of the subject is the influence which thedesiresandemotionshave upon the character both of the perceptions and conceptions with which they coexist.
It will be found that oursensationsvary in vividness and distinctness according to the strength and permanency of certain feelings of desire which coexist with them. For example, we are continually hearing a multitude of sounds, but in respect to many of them, as we feel no desire to know the cause or nature of them, these sensations are so feeble and indistinct as scarcely ever to be recalled to the mind or recognized by any act of memory; but should we hear somestrange wailing sound, immediately the desire would arise to ascertain its nature and cause. It would immediately become an object of distinct and vivid perception, and continue so as long as the desire lasted.
While one sensation becomes thus clear and prominent, it will be found that other sensations which were coexisting with it will become feebler and seem to die away. The same impressions may still be made upon the eye as before, the same sounds that had previously been regarded may still strike upon the ear, but while the desire continues to learn the cause of that strange wailing sound, the other sensations would all be faint and indistinct. When this desire is gratified, then other sensations would resume their former distinctness and prominency.
Ourconceptions, in like manner, are affected by the coexistence of emotion or desire. If, for example, we are employing ourselves in study or mental speculations, the vividness of our conceptions will vary in exact proportion to the interest we feel in securing the object about which our conceptions are employed. If we feel but little interest in the subject of our speculations, every conception connected with them will be undefined and indistinct; but if the desire of approbation, or the admonitions of conscience, or the hope of securing some future good stimulate desire, immediately our conceptions grow more vivid and clear, and the object at which we aim is more readily and speedily secured. The great art, then, of quickening mental vigor and activity, and of gaining clear and quick conceptions, is to awaken interest and excite desire. When this is secured, conceptions will immediately becomebright and clear, and all mental operations will be carried forward with facility and speed.
The distinction betweenattentionandabstractionis not great, but, as it is recognized in language, it needs to be definitely understood.Attentionhas been defined as "the direction of the mind to some particular object, from the interest which is felt in that object." It consists simply in a feeling of desire coexisting with our sensations and conceptions, and thus rendering them vivid and distinct; while, in consequence of this fact, all other sensations and conceptions seem to fade and grow indistinct.
Attention seems to be the generic exercise, and abstraction one species of the same thing. Attention is used to express the interest which attends our perceptions or conceptions aswhole objects, thus rendering them clear and distinct from other surrounding objects. Abstraction is that particular act of attention which makesone partorone qualityof a complex object become vivid and distinct, while other parts and qualities grow faint and indistinct. Thus, in viewing a landscape, we should be said to exercise the power of attention if we noticed some object, such as a stream or a bridge, while other objects were more slightly regarded; and we should exercise the power of abstraction if we noticed thecolorof the bridge or thewidthof the stream, while their other qualities were not equally regarded.
It is the power of abstraction which is the foundation oflanguagein its present use. Were it not for the power which the mind has of abstracting certain qualities and circumstances of things, and consideringthem as separate and distinct from all other parts and qualities, no words could be used except such as specify particular individuals. Every object that meets our eye would demand a separate and peculiar name, thus making the acquisition of language the labor of a life.
But now the mind possesses the power of abstracting a greater or fewer number of qualities, and to thesequalitiesa name is given, and whenever these qualities are found combined in any object, this name can be applied. Thus the nameanimalis given to any thing which has the qualities of existence and animal life, and the namequadrupedis given to any object which has the qualities of animal life and of four legs.
Every thing which is regarded by the mind as a separate existence must have some peculiar quality, or action, or circumstance of time or place, to distinguish it from every other existence. Were there not something, either in the qualities or circumstances, which made each object in some respects peculiar, there would be no way to distinguish one thing from another.
Aproper nameis one which is used to recall the properties and circumstances which distinguish one individual existence from every other. Such is the word Mount Blanc, which recalls certain qualities and circumstances that distinguish one particular thing from all others, and the name Julius Cæsar, which recalls the character, qualities, and circumstances which distinguish one being from every other.
Some words, then, are used to recall the peculiar qualities and circumstances of individual existences, and are calledproper names; other words are used torecall a combination of certain qualities and circumstances, which unitedly are an object of conception, but are not considered by the mind as belonging to any real particular existence. These last words are calledgeneral termsorcommon names.
A great variety of names may be applied to the same object of conception or perception, according to the number of qualities and circumstances which are abstracted by the mind. Thus an object may be called athing, and, in this case, the simple circumstance of existence is what is recalled by the word. The same object may be called ananimal, and then the qualities of existence and animal life are made the objects of conception. It can also be called aman, and then, in addition to the qualities recalled by the word animal, are recalled those qualities which distinguish man from all other animals. It can also be called afather, and then to the qualities recalled by the term man is added the circumstance of his relation to some other being. The same object can be calledLa Fayette, and then, to all the preceding qualities, would be added in our conceptions all those peculiar qualities and circumstances which distinguish the hero of France from all other existences.
The following will probably illustrate the mode by which the human mind first acquires the proper use of these general terms. The infant child learns to distinguish one existence from another probably long before he acquires the use of any names by which to designate them. We may suppose that a little dog is an inmate of his nursery, and that with thesightof this animal has often been associated thesoundof the worddog. This is so often repeated, that, by the principle of association, the sight of the object and the sound of the word invariably recur together. He observes that this sound is used by those around him in order to direct his attention to the animal, and he himself soon uses the word to direct the attention of others in the same way.
But soon it happens that another animal is introduced into his apartment, which in many respects resembles the object he has learned to call a dog. To this new object he would apply the same term, but he finds that others use the soundcatin connection with the sight of this new animal. He soon learns the difference between the two objects, the particulars in which they agree, and those in which they differ. He afterward notices other animals of these species, and observes that some have the qualities to which the termdogis applied, and others those to which the termcatis applied.
He continues to notice animals of other kinds, and, after long experience in this way, he learns to apply names to designate a particularcombination of qualities, and, whenever these qualities are found combined, he has a term ready to apply to them. He learns that some words are used to point out the peculiar qualities which distinguish one thing from all others, and, at the same time, other words are used which simply recallqualities, but do not designate any particular existence to which they belong. Thus the termboyhe uses for the purpose of designating qualities without conceiving of any particular existence in which they are found, while the termMaryis used to designatethe qualities and circumstances of the particular existence he finds as the companion of his sports.
All objects of our perceptions are arranged into classes, according to the peculiar combination of qualities which are recalled by the names employed to designate them. For example, all objects that have the qualities of existence and of animal life are arranged in one class, and are calledanimals. All those which have the qualities recalled by the term animal, and the additional qualities of wings and feathers, are arranged in another class calledbirds. All those objects which have the qualities included in the termbird, together with several additional qualities, are arranged in another class, and calledeagles.
To these various classes the termsgeneraandspeciesare applied. These terms imply arelation, or the comparison of one class with another, in reference to thenumber of qualitiesto be recalled by the terms employed. Thus the classbirdis called aspeciesof the classanimal, because it includes all the qualities that are combined in the conception recalled by the word animal, and others in addition; but the classbirdis called agenusin relation to the classeagle, because it contains only a part of the qualities which are recalled by the term eagle.
Agenusmay be defined as a class of things the name of which recallsfewerparticulars than the name of another class or species with which it is compared.Birdis agenuswhen compared with the classeagle.
Aspeciesis a class of things the name of which recalls more particulars than the name of another class or genus with which it is compared.Birdis aspecieswhen compared with the classanimal.
In examining language, it will be found that the larger portion of words in common use are names ofgeneraandspecies—that is, they are words employed to recall ideas as they are arranged in genera and species. It is only those words that areproper nameswhich recall conceptions of the particular existences by which we are surrounded. Some of these surrounding existences are furnished with these particular names, and others can be designated and distinguished from each other only by a description. Thus we see some hills around our horizon, some of which have a peculiar name, and others can be designated only by describing the circumstances which distinguish them from all other hills.
Adefinitionof a word is an enumeration of the several qualities or circumstances which distinguish certain things from all others, and which are recalled to the mind when the word is used. Thus, if the word animal is to be defined, we do it by mentioning the circumstances of itsexistenceandanimal life, as the ideas recalled by the word. Generally, a word is defined by mentioning the name of somegenusof which the thing intended is aspecies, and then adding those particular qualities which the species has, in addition to those included under the genus. Thus, if we are to define the wordman, we mention the genusanimal, and then the qualities which man has in addition to those possessed by other animals. Thus: "Manis ananimal, having the human form, and a spirit endowed with intellect, susceptibility, and will."
There are some words which recall onlyonequality or circumstance, and which, therefore, can not be defined like the words which recall various qualities andcircumstances, as joy, sorrow, color, and the like. Such words as these are defined by mentioning the times or circumstances when the mind is conscious of the existence of the idea to be recalled by the word. Thusjoyis "a state of mind which exists when any ardent desire is gratified."Coloris "a quality of objects which is perceived when light enters the eye."
Those conceptions which can be defined by enumerating the several qualities and circumstances which compose them are calledcomplex ideas, and the words used to designate them are calledcomplex terms. Such words as landscape, wrestler, giant, and philosopher, are complex terms. The word landscape recalls a complex idea of various material things. The word wrestler recalls an idea of a material object and one of its actions. The word giant recalls an idea of a thing and its relation as to size. The word philosopher recalls the idea of a thing and one of its qualities.
Those conceptions which are not composed of several qualities and circumstances, but are themselves a single quality or circumstance, are calledsimple ideas, and the words used to recall them are calledsimple terms. Such words as sweetness, loudness, depth, pain, and joy, are simple terms. Some terms which express emotions of the mind are entirely simple, such as sorrow, joy, and happiness. Others are words which recall an idea of a simple emotion and of itscause, such, for example, asgratitude, which expresses the idea of an emotion of mind and also that it was caused by some benefit conferred. Words that express simple ideas can be defined only by some description of the circumstances in which these ideas exist, or by a reference to their causes or effects.
Thecauses of the particular succession of our ideas, and the control which the mind has in regulating this succession, is a subject no less interesting than important; for if by any act of choice the mind has the power of regulating its own thoughts and feelings, then man is a free agent and an accountable being; but if the conceptions and the emotions depend entirely upon the constitution of things, and thus, either directly or indirectly, on the will of the Creator, then man can not be accountable for that over which he can have no control.
In the preceding chapter has been illustrated the effect which the co-existence of desire has in regard both to our sensations and our conceptions, tending to make those which are fitted to accomplish the object desired very vivid and prominent, while others, to a greater or less extent, disappear.
The mind is continually under the influence of some desire. It constantly has some plan to accomplish, some cause to search out, or some gratification to secure. The present wish or desire of the mind imparts an interest to whatever conception seems calculated to forward this object. Thus, if the mathematician has a problem to solve, and this is the leading desire of the mind, among the various conceptions that arise, those are the most interesting which are fitted to hisobject, and such immediately become vivid and distinct. If the painter or the poet is laboring to effect some new creation of his art, and has this as the leading object of desire, whatever conceptions seem best fitted to his purpose are immediately invested with interest, and become distinct and clear. If the merchant, or the capitalist, or the statesman has some project which he is toiling to accomplish, whatever conceptions appear adapted to his purpose soon are glowing and defined, in consequence of the interest with which desire thus invests them.
From this it appears that the nature of the desire, or governing purpose of the mind, will in a great measure determine the nature and the succession of its conceptions. If a man has chosen to find his chief happiness in securing power and honor, then those conceptions will be the most interesting to his mind that best fall in with his object. If he has chosen to find happiness in securing the various gratifications of sense, then those conceptions that most coincide with this desire will become prominent. If a man has chosen to find his chief enjoyment in doing the will of God, then his conceptions will, to a great extent, be conformed to this object of desire. The current of a man's thoughts, therefore, becomes the surest mode of determining what is the governing purpose or leading desire of the mind.
But there are seasons in our mental history when the mind does not seem to be under the influence of any governing desire; when it seems to relax, and its thoughts appear to flow on without any regulating principle. At such times the vividness of leadingconceptions, which otherwise is determined bydesire, seems to depend upon our past experience. Those objects which, in past experience, have been associated with emotion, are those which the mind selects, and which thus begin to glow in the distinct lineaments with which emotion at first invested them.
In past experience, all conceptions which were attended with emotion were most distinct and clear, and therefore, when such conceptions return united with others, they are the ones which are most interesting, and thus most vivid and distinct. Thus, in our musing hours of idle reverie, as one picture after another glides before the mind, if some object occurs, such as the home of our youth, or the friend of our early days, the emotions which have so often been united with these objects in past experience cause them to appear in clear and glowing lineaments, and the stronger have been the past emotions connected with them, the more clearly will they be defined. It appears, then, that there are two circumstances that account for the apparentselectionwhich the mind makes in its objects of conception. The first is the feeling thatcertain conceptions are fitted to accomplish the leading desire of the mind; and the second is, thatcertain objects in past experience have been attended with emotion.
But there is another phenomenon in our mental history which has a direct bearing on the nature and succession of our conceptions. When any conception, through the influence of desire or emotion, becomes the prominent object, immediately other objects with which this has been associated in past experience begin to return and gather around it in new combinations.Thus a new picture is presented before the mind, from which it again selects an object according as desire or emotion regulates, which, under this influence, grows vivid and distinct. Around this new object immediately begin to cluster its past associates, till still another scene is fresh arrayed before the mind.
In these new combinations, those objects which are least interesting continually disappear, while those most interesting are retained to form a part of the succeeding picture. Thus, in every mental picture, desire or emotion seems to call forth objects which start out, as it were, in bold relief from all others, and call from the shade of obscurity the companions of their former existence, which gather around them in new and varied combinations.
Almost every object of thought in past experience has been connected with a great number of other objects, and so great has been the variety of its former combinations, that it would be impossible to predict, with any degree of certainty,whichof its past associates will be summoned to aid in forming the new mental scenes which are destined to arise. Yet experience has enabled us to detect somegeneral laws, which appear to regulate these combinations.
Thefirstis, that those objects are most likely to attend each other which in past experience were united, while some strong emotion was existing with them. If, for example, a retired lake had been the scene of death to a beloved friend, the conception of this object would be almost invariably associated with the image of the friend that had perished beneath its waters, and also with the scene of his death. In like manner, ifsome friend had expired at a certain hour of the day, or on a particular day of the year, the return of these seasons would probably be associated with the sorrowful scenes connected with them in past experience.
Thesecondlaw of association is, thatlong continuedorfrequently repeatedattention to objects that are connected at the time of this attention will secure the connected return of these objects.Attention, it may be recollected, is desire united with our conceptions, thus rendering them more vivid.
It seems to produce the same effect if this attention is long continued or if it is frequently repeated. Thus, if the mind has dwelt for a long time on a beautiful picture, has noticed all its proportions, its shading, its outline, and its colors with minute attention, one object in this picture can not recur to the mind without bringing with it the other objects that were associated at the time of this close attention. The frequent repetition of a sentence is a case whereoft repeatedthough short attention to certain words has the effect of recalling them to the mind in the connection in which they were placed during this repeated attention.
Thethirdlaw of association is, that objects which haverecentlybeen associated in experience are, on this account, more likely to recall each other than to recall those which were connected with them at a more remote period of time. The passage of time, as a general fact, seems to weaken the vividness of our conceptions, and to destroy the probability of their associate recurrence. Thus a line of poetry may be repeated, and the listener may be able, the moment after, to recalleach word, but the next day the whole may be lost.
Thefourthlaw of association is, that the recurrence of associated objects depends, in a great measure, upon thenumberof objects with which it may have been connected in past experience. If it has existed in combination with onlyoneobject, that object will return associated with it; but in proportion as the number of its associates increases, the power of determining which will be its next companion diminishes. As an example of this fact may be mentioned the first hearing of a beautiful air by some particular person. The next time it is heard, the idea of this performer will be associated with the sounds; but after it has been sung by a great variety of persons, other circumstances would determine what conceptions this air would recall. It is very probable, in this case, that its notes would recall from among the associated scenes the friend most beloved, or some interesting circumstance that awakened emotion at the time the air was performed.
The principal circumstances which operate in recalling associated ideas have now been pointed out. The next inquiry is, What are those objects and events which ordinarily are most frequently united in ourperceptions, and therefore are most likely to return together in ourconceptions?
The most common connection of our ideas of perception are made by contiguity inplace. Objects are continually passing before the eye, and they are not in single distinct objects, but in connected groups. Of course, when we perceive any object, we must necessarilyobserve its several relations to the things by which it is surrounded. If it is a building which meets the eye, it is impossible to observe it without at the same time perceiving the trees around it, the sky above it, and any other objects which are parts of the picture of which this is the prominent object. Of course, objects that are united in one complex picture before the eye when we gain our knowledge of them by perception, will ordinarily return together in our conceptions.
Our ideas, also, are very much connected by contiguity as it respectstime. When any two events occur at the same moment of time, or in such near connection that the conception of one remains until the other occurs, they ordinarily will recur together in our after conceptions of them. As an example of this may be mentioned the associations of a family who have been accustomed to close each Sabbath with music. As the still hour of this sacred evening drew on, wherever any wanderer might roam, it is probable that the notes of praise, so often connected with this season, would perpetually steal over the mind, bringing many another image of friends, and kindred, and home.
The mind of man is so constituted that no change can take place in any material object without awakening the idea of somecause. Aneffectis defined as "some change of state or mode of existence in matter or mind." Acauseis defined as "that without which no change would take place in matter or mind, and with which it will take place." As the ideas of cause and effect are so constantly conjoined in all our acts of perception, these ideas will return together in ourconceptions. Thus, if we see an instrument which has been the cause of pain, the idea of this effect will be recalled by a conception of the cause; or if the mind is dwelling on the memory of some beautiful painting or poetry, the author of these works will probably recur to the mind in connection with these conceptions.
We sometimes meet with persons of such peculiar habits and dispositions, that, whenever they are encountered, the feelings are wounded or the temper crossed by their ill-timed or ill-natured remarks. The conceptions of such persons will ordinarily be attended by the memory of some pains of which they have been the cause, and the mind will involuntarily shrink from contact with them, as from the points and thorns of a bramble-bush. Those events, therefore, or those objects which have the relation ofcauseandeffectexisting between them, will ordinarily be united as objects of conception.
The mind of man is continually noticing therelationswhich exist between the different objects of its conceptions. As no idea of relation can be gained without comparing two or more things together, those objects which are most frequentlycomparedwill naturally be most frequently associated together in our conceptions. It has been shown that language is founded on that principle of the mind which enables us to notice certain qualities in things abstracted from other qualities, and to apply names to objects according as we find certain qualities united in them. Of course, in the use of language, the mind is continually led to notice the particulars in which objects resemble each other,and also the particulars in which they differ; consequently the mind, in learning and in applying names, is continually comparing objects, both to discover the particulars in which they are alike and those in which they differ, so that two objects are thus brought together before the mind.
It is owing to this fact, therefore, that objects which resemble each other, or which are very much contrasted in their qualities, are very commonly united in our conceptions. If, for example, we see the countenance of a stranger, some feature will be recognized as familiar. Desire will be awakened to know where and in what other countenance we have seen such a feature or such an expression. This particular feature will thus become abstracted and vivid, and will soon recall that other combination of features for which we are seeking, and of which this has formed a part in our past experience. Thus two objects will be brought before the mind at once, the person who is the stranger, and a conception of another person whom this stranger resembles.
All our ideas of contrast are relative. One thing can not be conceived of as very high or very low, as very large or very small, without a previous comparison with some object to determine this relation. Our ideas of poverty and riches, or of happiness and misery, are alsorelative. A person is always considered poor or rich, happy or miserable, by comparing his lot with that of others by whom he is surrounded. As, therefore, all ideas of resemblance or of contrast are gained by comparing two objects together, our conceptions often unite objects thatresembleeach other or that arecontrastedwith each other.