NECESSARY AND SUFFICIENT CONDITIONS OF TRUE ABSOLUTE CAUSALITY.
102. We have just seen that the necessary connection of two objects is not enough to establish the character of causality; what circumstances are then necessary?
103. If we conceive an object, B, which begins, and suppose that the object A wasnecessaryto its existence, and thatof itself aloneit was sufficient for the existence of B, we find in the relation of A to B the true character of the relation of a cause to its effect. For the complete character ofabsolutecause, two conditions are indispensable: I. The necessity of the existence of A for the existence of B. II. That the existence of A be sufficient for the existence of B, without any thing more being requisite.
These conditions may be expressed in the following propositions or formulas:
If B exists, A exists.
The existence of A alone is sufficient for the existence of B.
When the relation between two objects is such that both these propositions are true at the same time, there is a relation of absolute causality.
104. From this explanation it is evident that the character of cause must be denied to all mere occasions, since the second proposition cannot be applied to them. When two facts are occasionally connected, it may be said that if the one exists the other must exist, and the first proposition is verified in this case; but it cannot be said that the existence ofthe one is sufficient for the existence of the other; and therefore the second proposition fails of its application. If two men have agreed that the one shall fire a pistol when the other gives a signal with his hand, it may be said that if the signal is given the pistol will be fired, but not that the signal alone contains what is sufficient for the firing of the pistol. For, supposing the man with the pistol to be asleep, the signal may be repeated a number of times without the firing of the pistol.
105. The character of cause must also be denied to every condition which is only the removal of an obstacle (removens prohibens). To such the first proposition is applicable, but not the second. In the case of a body resting on a pillar so that it cannot fall unless the pillar be removed, we may say: if the body has fallen, the pillar has been taken away; but not that the removal of the pillar is sufficient for the fall of the body; because if the body were of a less specific gravity than the fluid in which it is submerged, or united to another body which would prevent its falling, it would not fall. It is evident that the removal of the obstacle is not sufficient for the fall, but that something more is required, as the force of gravity, or an impulse.
106. All phenomena connected in succession of time necessarily and in a fixed order, must be denied the relation of cause and effect, unless the application of these ideas is made legitimate by something else; because, although the constant order authorizes us to say that if A happens, B will happen, and then C, and then D, and so on successively, it cannot be said that in the existence of A is contained that which is sufficient for the existence of B, nor in the existence of B what is sufficient for the existence of C, since we suppose an indispensable condition outside of the series.
107. The first proposition: if B exists, A exists; is true of every cause whether necessary or free. The second proposition is likewise applicable to both these classes of causes. It is necessary to observe with care that the proposition does not say that if A exists, B will exist; but that the existence of A is all that is requisite in order that Bmayexist. If, supposing A, B is necessarily supposed also, the cause is necessary; but if, supposing A, only that which is sufficient for the existence of B is supposed, the cause remains free; because the existence of B is not affirmed, but only the possibility of its existence.
108. Let us apply this doctrine to the first cause. If the world exists, God exists: this proposition is absolutely true. If God exists, the world exists; this proposition is false, because, God existing, the world might not have existed. If God exists, the world may exist; that is, in the existence of God is contained that which is sufficient for the possibility of the existence of the world: this proposition is true; because in the infinite being is contained the possibility of finite beings, and in him is found sufficient power to give them existence, if he thus freely wills it.