On Animals (De Animalibus)

history
that is, final cause
because it is, final cause

Why is it [the final cause]

Whence it comes and
reaches the end

On generation. History holds the first place: and as the name itself signifies, it contains the exposition of the thing: what it is, or how it comes to be—which the schools of philosophers of our age are accustomed to call "because it is." Soon, the books "On the Parts" and "On Generation" declare the cause of why it is so: the one primarily the final, the other the efficient; for since we ought to possess the thing whose cause we wish to render through a verified knowledge of "what it is," it is rightly written both as a history of animals, and it precedes the teaching of causes—from whence, or to what end, or for whose sake each thing was founded by nature; primarily, I say, the final and efficient cause; for, as occasion permits, the material cause is also explained here and there for the sake of the subject, so that at once the reason for necessity and of the better arrangement may be declared, or from what and whence each thing consists may be demonstrated. But although this interpretation of the histories is completed in nine books, I have nevertheless placed here as the seventh what is contained as the ninth in the Greek exemplar, and I do not think this was done rashly. For it treats in that [book] of the generation of man, which thing Aristotle promises will be explained continuously from the generation of other animals. Therefore, since he had exposed the generation of other animals in the fifth and sixth books, it should be in no doubt that he placed this as the seventh. But Andronicus of Rhodes [Appellicon of Teos], concerning whom Strabo says much—just as he corrupted many other things in the writing of the Aristotelian books—thus seems to have transposed this, thinking it should be placed as the last of the whole history, since when Aristotle began to treat of generation, he promised that he would speak of man in the last place. But he did not speak of it as the last of the entire history, but as the last of that place which is about generation; completing that passage, he writes: "It follows," he says, "that in a like manner we should discuss those things which bring forth young in the genus of terrestrial animals, and also concerning man." Therefore, this third from the first is to be placed on generation, whereby it happens that this same is held as the seventh in the order of the whole history. There are also copies, both Greek and indeed Latin, which have a certain fragment added to the histories, but it explains certain material and efficient causes of human generation; it does not embrace the history. Therefore, not