| First, That reason alone can never give rise to any original idea, and secondly, that reason, as distinguished from experience, can never make us conclude, that a cause or productive quality is absolutely requisite to every beginning of existence. |
| Both these considerations have been sufficiently explained: and therefore shall not at present be any farther insisted on. |
| I shall only infer from them, that since reason can never give rise to the idea of efficacy, that idea must be derived from experience, and from some particular instances of this efficacy, which make their passage into the mind by the common channels of sensation or reflection. |
| Ideas always represent their objects or impressions; and vice versa, there are some objects necessary to give rise to every idea. |
| If we pretend, therefore, to have any just idea of this efficacy, we must produce some instance, wherein the efficacy is plainly discoverable to the mind, and its operations obvious to our consciousness or sensation. |
| By the refusal of this, we acknowledge, that the idea is impossible and imaginary, since the principle of innate ideas, which alone can save us from this dilemma, has been already refuted, and is now almost universally rejected in the learned world. |
| Our present business, then, must be to find some natural production, where the operation and efficacy of a cause can be clearly conceived and comprehended by the mind, without any danger of obscurity or mistake. |
| In this research we meet with very little encouragement from that prodigious diversity, which is found in the opinions of those philosophers, who have pretended to explain the secret force and energy of causes. |
| [See Father Malbranche, Book VI. Part 2, chap. 3 And the illustrations upon it.] There are some, who maintain, that bodies operate by their substantial form; others, by their accidents or qualities; several, by their matter and form; some, by their form and accidents; others, by certain virtues and faculties distinct from all this. |
| All these sentiments again are mixed and varyed in a thousand different ways; and form a strong presumption, that none of them have any solidity or evidence, and that the supposition of an efficacy in any of the known qualities of matter is entirely without foundation. |
| This presumption must encrease upon us, when we consider, that these principles of substantial forms, and accidents, and faculties, are not in reality any of the known properties of bodies, but are perfectly unintelligible and inexplicable. |
| For it is evident philosophers would never have had recourse to such obscure and uncertain principles, had they met with any satisfaction in such as are clear and intelligible; especially in such an affair as this, which must be an object of the simplest understanding, if not of the senses. |
| Upon the whole, we may conclude, that it is impossible in any one instance to shew the principle, in which the force and agency of a cause is placed; and that the most refined and most vulgar understandings are equally at a loss in this particular. |
| If any one think proper to refute this assertion, he need not put himself to the trouble of inventing any long reasonings: but may at once shew us an instance of a cause, where we discover the power or operating principle. |
| This defiance we are obliged frequently to make use of, as being almost the only means of proving a negative in philosophy. |
| The small success, which has been met with in all the attempts to fix this power, has at last obliged philosophers to conclude, that the ultimate force and efficacy of nature is perfectly unknown to us, and that it is in vain we search for it in all the known qualities of matter. |
| In this opinion they are almost unanimous; and it is only in the inference they draw from it, that they discover any difference in their sentiments. |
| For some of them, as the CARTESIANS in particular, having established it as a principle, that we are perfectly acquainted with the essence of matter, have very naturally inferred, that it is endowed with no efficacy, and that it is impossible for it of itself to communicate motion, or produce any of those effects, which we ascribe to it. |
| As the essence of matter consists in extension, and as extension implies not actual motion, but only mobility; they conclude, that the energy, which produces the motion, cannot lie in the extension. |
| This conclusion leads them into another, which they regard as perfectly unavoidable. |
| Matter, say they, is in itself entirely unactive, and deprived of any power, by which it may produce, or continue, or communicate motion: But since these effects are evident to our senses, and since the power, that produces them, must be placed somewhere, it must lie in the DEITY, or that divine being, who contains in his nature all excellency and perfection. |