Page 70 of 96
'Twill only be proper, before we leave this subject, to draw some corollaries from it, by which we may remove several prejudices and popular errors that have very much prevailed in philosophy. First, we may learn, from the foregoing doctrine, that all causes are of the same kind, and that, in particular, there is no foundation for that distinction which we sometimes make betwixt efficient causes, and causes sine qua non; or betwixt efficient causes, and formal, and material, and exemplary, and final causes. For as our idea of efficiency is derived from the constant conjunction of two objects, wherever this is observed, the cause is efficient; and where it is not, there can never be a cause of any kind. For the same reason we must reject the distinction betwixt cause and occasion, when supposed to signify any thing essentially different from each other. If constant conjunction be implied in what we call occasion, 'tis a real cause; if not, 'tis no relation at all, and cannot give rise to any argument or reasoning.
Secondly, the same course of reasoning will make us conclude, that there is but one kind of necessity, as there is but one kind of cause, and that the common distinction betwixt moral and physical necessity is without any foundation in nature. This clearly appears from the precedent explication of necessity. 'Tis the constant conjunction of objects, along with the determination of the mind, which constitutes a physical necessity: and the removal of these is the same thing with chance. As objects must either be conjoined or not, and as the mind must either be determined or[Pg 227] not to pass from one object to another, 'tis impossible to admit of any medium betwixt chance and an absolute necessity. In weakening this conjunction and determination you do not change the nature of the necessity; since even in the operation of bodies, these have different degrees of constancy and force, without producing a different species of that relation.
The distinction, which we often make betwixt power and the exercise of it, is equally without foundation.
Thirdly, we may now be able fully to overcome all that repugnance, which 'tis so natural for us to entertain against the foregoing reasoning, by which we endeavoured to prove, that the necessity of a cause to every beginning of existence is not founded on any arguments either demonstrative or intuitive. Such an opinion will not appear strange after the foregoing definitions. If we define a cause to be an object precedent and contiguous to another, and where all the objects resembling the former are placed in a like relation of priority and contiguity to those objects that resemble the latter; we may easily conceive that there is no absolute nor metaphysical necessity, that every beginning of existence should be attended with such an object. If we define a cause to be, an object precedent and contiguous to another, and so united with it in the imagination, that the idea of the one determines the mind to form the idea of the other, and the impression of the one to form a more lively idea of the other; we shall make still less difficulty of assenting to this opinion. Such an influence on the mind is in itself perfectly extraordinary and incomprehensible; nor can we be certain of its reality, but from experience and observation.
I shall add as a fourth corollary, that we can never have reason to believe that any object exists, of which[Pg 228] we cannot form an idea. For, as all our reasonings concerning existence are derived from causation, and as all our reasonings concerning causation are derived from the experienced conjunction of objects, not from any reasoning or reflection, the same experience must give us a notion of these objects, and must remove all mystery from our conclusions. This is so evident that 'twould scarce have merited our attention, were it not to obviate certain objections of this kind which might arise against the following reasonings concerning matter and substance. I need not observe, that a full knowledge of the object is not requisite, but only of those qualities of it which we believe to exist.
[12] Sect. 2.
[13] See Mr Locke; chapter of Power.
[14] See Father Malebranche, Book VI. Part II. Chap. 3, and the illustrations upon it.
[15] The same imperfection attends our ideas of the Deity; but this can have no effect either on religion or morals. The order of the universe proves an omnipotent mind; that is, a mind whose will is constantly attended with the obedience of every creature and being. Nothing more is requisite to give a foundation to all the articles of religion; nor is it necessary we should form a distinct idea of the force and energy of the Supreme Being.
[16] Section 6.
[17] Part IV. sect 5.
According to the precedent doctrine, there are no objects which, by the mere survey, without consulting experience, we can determine to be the causes of any other; and no objects which we can certainly determine in the same manner not to be the causes. Any thing may produce any thing. Creation, annihilation, motion, reason, volition; all these may arise from one another, or from any other object we can imagine. Nor will this appear strange if we compare two principles explained above, that the constant conjunction of objects determines their causation,[18] and that, properly speaking, no objects are contrary to each other but existence[Pg 229] and non-existence. Where objects are not contrary, nothing hinders them from having that constant conjunction on which the relation of cause and effect totally depends.
Since, therefore, 'tis possible for all objects to become causes or effects to each other, it may be proper to fix some general rules by which we may know when they really are so.
1. The cause and effect must be contiguous in space and time.
2. The cause must be prior to the effect.
3. There must be a constant union betwixt the cause and effect. 'Tis chiefly this quality that constitutes the relation.
4. The same cause always produces the same effect, and the same effect never arises but from the same cause. This principle we derive from experience, and is the source of most of our philosophical reasonings. For when by any clear experiment we have discovered the causes or effects of any phenomenon, we immediately extend our observation to every phenomenon of the same kind, without waiting for that constant repetition, from which the first idea of this relation is derived.
5. There is another principle which hangs upon this, viz. that where several different objects produce the same effect, it must be by means of some quality which we discover to be common amongst them. For as like effects imply like causes, we must always ascribe the causation to the circumstance wherein we discover the resemblance.
