6. But, it may be asked, how do those who have written to prove the existence of the Deity reply to such an objection as the one just stated? It is natural to suppose that, on a subject so interesting and so long discussed, all the obvious arguments with their replies, have been fully brought into view. What is the result in this case? [319]
The principal modes of replying to the above objection, that the series of causes and effects which now exists, may have existed from eternity, appear to be these.
In the first place, our minds cannot be satisfied with a series of successive, dependent, causes and effects, without something first and independent. We pass from effect to cause, and from that to a higher cause, in search of something on which the mind can rest; but if we can do nothing but repeat this process, there is no use in it. We move our limbs, but make no advance. Our question is not answered, but evaded. The mind cannot acquiesce in the destiny thus presented to it, of being referred from event to event, from object to object, along an interminable vista of causation and time. Now this mode of stating the reply,—to say that the mind cannot thus be satisfied, appears to be equivalent to saying that the mind is conscious of a Principle, in virtue of which such a view as this must be rejected;—the mind takes refuge in the assumption of a First Cause, from an employment inconsistent with its own nature.
7. Or again, we may avoid the objection, by putting the argument for the existence of a Deity in this form: The series of causes and effects which we call the world, or the course of nature, may be considered as a whole, and this whole must have a cause of its existence. The whole collection of objects and events may be comprehended as a single effect, and of this effect there must be a cause. This Cause of the Universe must be superior to, and independent of the special events, which, happening in time, make up the universe of which He is the cause. He must exist and exercise causation, before these events can begin: He must be the First Cause.
Although the argument is here somewhat modified in form, the substance is the same as before. For the assumption that we may consider the whole series of causes and effects as a single effect, is equivalent to the assumption that besides partial causes we must have a First Cause. And thus the Idea of a First Cause, and [320] the axiom which asserts its necessity, are recognized in the usual argumentation on this subject.
8. This Idea of a First Cause, and the principle involved in the Idea, have been the subject of discussion in another manner. As we have already said, we assume as an axiom that a First Cause must exist; and we assert that God, the First Cause, exists eternal and immutable, by the necessity which the axiom implies. Hence God is said to exist necessarily;—to be a necessarily existing being. And when this necessary existence of God had been spoken of, it soon began to be contemplated as a sufficient reason, and as an absolute demonstration of His existence; without any need of referring to the world as an effect, in order to arrive at God as the cause. And thus men conceived that they had obtained a proof of the existence of the Deity, à priori, from Ideas, as well as à posteriori, from Effects.
9. Thus, Thomas Aquinas employs this reasoning to prove the eternity of God[29]: ‘Oportet ponere aliquod primum necessarium quod est per se ipsum necessarium; et hoc est Deus, cum sit prima causa ut dictum est: igitur Deus æternus est, cum omne necessarium per se sit æternum.’ It is true that the schoolmen never professed to be able to prove the existence of the Deity à priori: but they made use of this conception of necessary existence in a manner which approached very near to such an attempt. Thus Suarez[30] discusses the question, ‘Utrum aliquo modo possit à priori demonstrari Deum esse.’ And resolves the question in this manner: ‘Ad hunc ergo modum dicendum est: Demonstrato à posteriori Deum esse ens necessarium et a se, ex hoc attributo posse à priori demonstrari præter illud non posse esse aliud ens necessarium et a se, et consequenter demonstrari Deum esse.’
[29] Aquin. Cont. Gentil. lib. i. c. xiv. p. 21.
[30] Metaphys. tom. ii. disp. xxix. sect. 3, p. 28.
But in modern times attempts were made by Descartes and Samuel Clarke, to prove the Divine [321] existence at once à priori, from the conception of necessary existence; which, it was argued, could not subsist without actual existence. This argumentation was acutely and severely criticised by Dr. Waterland.