A gratis assertion is first made, that all things we see are effects; then because we see one thing caused, every thing must have been caused. His conclusion of the argument is still more curious, "because every thing was caused there must have been something that was not caused." The cause ought to be proportioned to the effect. The effect is not infinite. Why then attribute infinity to the cause? This is Hume's argument. Priestley calls it shortly unworthy of a philosopher. Let others judge! But surely, with all this infinity it may be asked, why may not there have been an infinity of causes?
Another argument is, that being unable to account, for what is, by any thing visible, we must have recourse to something invisible, and that invisible power is what he calls God. Apply this argument to gravity, and the external force that is said to cause every stone to fall is God. But if nothing visible can to us account for the operations of nature, why must we have recourse to what is invisible? Why necessary to account at all for them? Or why may not visible things account for them, although this person or another cannot tell which?
If nothing can begin to exist of itself or by the energy of material nature, it is more consistent to allow a plurality of Deities, than one immediate Deity. An equality in a plurality of Deities might be objectionable. But that is not at all necessary, rather the contrary; and so was the Pagan theory, which is not so absurd as the modern one. This universe or mundane system may be the work of one hand, another of another, and so on. Where is the absurdity of that? If the universe is applied to the solar system, there is an appearance of its being formed by one design, and in that stile it might be said to be the work of one hand. But this Deity is asserted to be infinite, and to have made all other worlds and universes, though it does not appear by any unity of design that all other worlds and universes are one work with this.
Dr. Priestley himself allows that reason would drive us to require a cause of the Deity. He is himself obliged to conclude, after all his reasoning, that we must acquiesce in our inability of having any idea on the subject; that is, how God could exist without a prior cause. At the same time he says the Deity cannot have a cause, and therefore we cannot reason about him. Why then all his own reasoning? We make a Deity ourselves, fall down and worship him. It is the molten calf over again. Idolatry is still practised. The only difference is that now we worship idols of our imagination; before of our hands. "Still we must necessarily rest at a Being that is infinite;" that is, when our reason drives us to the admission of an infinite cause we must necessarily stop finitely in our career. Not content with this conclusion he adds, that we cannot help perceiving the existence of this cause, though he owns that it is not an object of our conceptions. But even the Theist's argument does not necessarily drive us to the admission of an infinite cause. The argument is, "because there is a man, and man has intelligence, we must necessarily admit of a Being of infinitely superior intelligence." Would it not be nearly as well to argue, "because there is a goose, therefore there must be a man."
What is there more which hinders a series of finite causes to be carried back ad infinitum, than that the reasoner or contemplator of the course of nature is tired. If this eternal series could not exist, a Deity might with some propriety be said to follow. Put the argument into a syslogistic form.
"The universe shews design;"
"It is absurd to suppose an infinite succession of finite causes;"
"Therefore there is an uncaused intelligent cause of this universe."
Deny the second assertion and the problem is destroyed. So far from its being difficult to suppose an eternity, it is the most difficult thing in the world to suppose any thing but an eternity. A mind, not afraid to think, will find it the most easy contemplation in the world to dwell upon. It is at least a bold assertion, that nothing can be more evident than that plants and animals could not have proceeded from each other by succession from all eternity. Surely to this may be answered, that it is more evident that two and two make four. But Dr. Priestley goes on to say, "that the primary cause of a man cannot be a man, any more than the cause of a sound can be a sound." Experience shews us all sound is an effect of a cause. Does experience shew us more of a man than that he came from a man and a woman? To allow therefore that all men must have come from a man and a woman is as far as we can argue upon the subject, whilst in reasoning we trust to experience. An argument is well built upon similarity, therefore it is probable if one horse had a cause all horses had. But will not the argument be more consonant to itself, in supposing all horses had the same cause, and as one is seen to be generated from a horse and a mare so all were from all eternity. It were a better argument in favour of a Deity or some invisible agent to shew that a new animal came every now and then into life, without any body's knowing how or where.
It is allowed by Priestley and all other reasoners, that the most capital argument that can be formed in support of any thesis is to be built upon experience, or analogy to experience. Yet will many of these reasoners, Dr. Priestley at least for one, contend at the same time for the probability of a future life, when no instance can be given of any revival whatsoever. The same will contend, that their Deity can at pleasure form new species of animals, though in fact we never do see new beings come into existence. We ought only to argue from experience; and experience would teach us, that the species of all animals has eternally existed. Grant that we do not know, whether man has been eternal, or from a time, is it therefore because we do not know, that we must say he came from God? That unknown Being, as he is sometimes pompously and ridiculously called! The Devil is equally an unknown Being. The admission of evil under a good Deity opens a ready door to the manichean system, which seems much more rational than simple Deism.