We may answer that the matter of which materialists speak, matter spontaneously and eternally mobile, active, productive, matter chemically or organically determined and manifested by the properties or forces, mechanical, physical, animal, and intelligent, which necessarily belong to it--that this matter has nothing in common with the _vile matter_ of the idealists. The latter, a product of their false abstraction, is indeed a stupid, inanimate, immobile thing, incapable of giving birth to the smallest product, a _caput mortuum_, an _ugly_ fancy in contrast to the _beautiful_ fancy which they call _God_; as the opposite of this supreme being, matter, their matter, stripped by them of all that constitutes its real nature, necessarily represents supreme nothingness. They have taken away from matter intelligence, life, all its determining qualities, active relations or forces, motion itself, without which matter would not even have weight, leaving it nothing but impenetrability and absolute immobility in space; they have attributed all these natural forces, properties, and manifestations to the imaginary being created by their abstract fancy; then, interchanging _rôles_, they have called this product of their imagination, this phantom, this God who is nothing, "supreme Being," and, as a necessary consequence, have declared that the real being, matter, the world, is nothing. After which they gravely tell us that this matter is incapable of producing anything, not even of setting itself in motion, and consequently must have been created by their God. At the end of this book I exposed the fallacies and truly revolting absurdities to which one is inevitably led by this imagination of a God, let him be considered as a personal being, the creator and organizer of worlds; or even as impersonal, a kind of divine soul spread over the whole universe and constituting thus its eternal principle; or let him be an idea, infinite and divine, always present and active in the world, and always manifested by the totality of material and definite beings. Here I shall deal with one point only. The gradual development of the material world, as well as of organic animal life and of the historically progressive intelligence of man, individually or socially, is perfectly conceivable. It is a wholly natural movement from the simple to the complex, from the lower to the higher, from the inferior to the superior; a movement in conformity with all our daily experiences, and consequently in conformity also with our natural logic, with the distinctive laws of our mind, which being formed and developed only by the aid of these same experiences, is, so to speak, but the mental, cerebral reproduction or reflected summary thereof.