Page:The System of Nature.djvu/114

 causes which actually act upon it, or which give it energy; that then the human species would change, to make place for new beings, suitable to co-order themselves with the state that should succeed to that which we now see subsist.

In thus supposing the changes in the position of our globe, the primitive man did, perhaps, differ more from the actual man, than the quadruped differs from the insect. Thus man, the same as every thing else that exists on our planet, as well as in all the others, may be regarded as in a state of continual vicissitude: thus the last term of the existence of man is to us as unknown and as indistinct as the first: there is, therefore, no contradiction in the belief that the species vary incessantly&mdash;that to us it is as impossible to know what he will become, as to know what he has been.

With respect to those who may ask why Nature does not produce new beings? we may enquire of them in turn, upon what foundation they suppose this fact? What it is that authorizes them to believe this sterility in Nature? Know they if, in the various combinations which she is every instant forming, Nature be not occupied in producing new beings, without the cognizance of these observers? Who has informed them that this Nature is not actually assembling, in her immense elaboratory, the elements suitable to bring to light, generations entirely new, that will have nothing in common with those of the species at present existing? What absurdity then, or what want of just inference would there be, to imagine that the man, the horse, the fish, the bird, will be no more? Are these animals so indispensably requisite to Nature, that without them she