Here it is permissible for the _archaeologist_ of nature to derive from the surviving traces of its oldest revolutions, according to all its mechanism known or supposed by him, that great family of creatures (for so we must represent them if the said thoroughgoing relationship is to have any ground). He can suppose the bosom of mother earth, as she passed out of her chaotic state (like a great animal), to have given birth in the beginning to creatures of less purposive form, that these again gave birth to others which formed themselves with greater adaptation to their place of birth and their relations to each other; until this womb becoming torpid and ossified, limited its births to definite species not further modifiable, and the manifoldness remained as it was at the end of the operation of that fruitful formative power.--Only he must still in the end ascribe to this universal mother an organisation purposive in respect of all these creatures; otherwise it would not be possible to think the possibility of the purposive form of the products of the animal and vegetable kingdoms.[120] He has then only pushed further back the ground of explanation and cannot pretend to have made the development of those two kingdoms independent of the condition of final causes. Even as concerns the variation to which certain individuals of organised genera are accidentally subjected, if we find that the character so changed is hereditary and is taken up into the generative power, then we cannot pertinently judge the variation to be anything else than an occasional development of purposive capacities originally present in the species with a view to the preservation of the race. For in the complete inner purposiveness of an organised being, the generation of its like is closely bound up with the condition of taking nothing up into the generative power which does not belong, in such a system of purposes, to one of its undeveloped original capacities. Indeed, if we depart from this principle, we cannot know with certainty whether several parts of the form which is now apparent in a species have not a contingent and unpurposive origin; and the principle of Teleology, to judge nothing in an organised being as unpurposive which maintains it in its propagation, would be very unreliable in its application and would be valid solely for the original stock (of which we have no further knowledge).