Are not theologians strange reasoners? Whenever they cannot divine the natural causes of things, they invent what they call supernatural; such as spirits, occult causes, inexplicable agents, or rather words, much more obscure than the things they endeavour to explain. Let us remain in nature, when we wish to account for the phenomena of nature; let us be content to remain ignorant of causes too delicate for our organs; and let us be persuaded, that, by going beyond nature, we shall never solve the problems which nature presents.

Even upon the hypothesis of theology, (that is, supposing an all-powerful mover of matter,) by what right would theologians deny, that their God has power to give this matter the faculty of thought? Was it then more difficult for him to create combinations of matter, from which thought might result, than spirits who could think? At least, by supposing matter, which thinks, we should have some notions of the subject of thought, or of what thinks in us; whereas, by attributing thought to an immaterial being, it is impossible to form the least idea of it.