ARISTOTLE TO AUGUSTINE On the Generation of Animals Aristotle does not claim to have founded the science of zoology, and his books contain copious citations of earlier writers, accompanied by a judicious degree of scepticism about some of their wilder reports However, his detailed observations of organisms of very various kinds were quite without precedent, and in many cases they were not superseded until the seventeenth century Though he does not claim to be the Wrst zoologist, Aristotle clearly saw himself as a pioneer, and indeed felt some need to justify his interest in the subject Previous philosophers had given a privileged place to the observation of the heavens, and here was he prodding sponges and watching the hatching of grubs In his defence he says that while the heavenly bodies are marvellous and glorious, they are hard to study because they are so distant and diVerent from ourselves Animals, however, are near at hand, and akin to our own nature, so that we can investigate them with much greater precision It is childish to be squeamish about the observation of the humbler animals ‘We should approach the investigation of every kind of animal without being ashamed, for each of them will exhibit to us something natural and something beautiful’ (PA 645a20–5) The scope of Aristotle’s researches is astonishing Much of his work is taken up with classiWcation into genus (e.g Testacea) and species (e.g seaurchin) More than 500 species Wgure in his treatises, and many of them are described in detail It is clear that Aristotle was not content with the observation of a naturalist: he also practised dissection like an anatomist He acknowledges that he found dissection distasteful, particularly in the case of human beings: but it was essential to examine the parts of any organism in order to understand the structure of the whole (PA 644b22–645a36) Aristotle illustrated his treatises with diagrams, now sadly lost We can conjecture the kind of illustrations he provided when we read passages such as the following, where he is explaining the relationship between the testicles and the penis In the accompanying diagram the letter A marks the starting point of ducts leading down from the aorta; the letters JJ mark the heads of the testicles and the ducts that descend to them; the ducts leading from them through the testicles are marked YY, and the reverse ducts containing white Xuid and leading to the testicles are marked ´´; the penis D, the bladder ¯ , and the testicles XX (HA 510a30–4) 71