Background
Eudemos was born in 370 B.C. on the Isle of Rhodes but spent a large part of his life in Athens. Nothing is known of his background except that he had a brother Boethus, who had a son, Pasicles.
Εὔδημος
Eudemos was born in 370 B.C. on the Isle of Rhodes but spent a large part of his life in Athens. Nothing is known of his background except that he had a brother Boethus, who had a son, Pasicles.
Eudemus was a pupil of Aristotle and studied philosophy at Aristotle's Peripatetic School. He won the master’s good opinion to such an extent that he and Theophrastus of Lesbos were known as Aristotle’s “companions.”
The main importance of Eudemus in the history of thought is that he, Theophrastus, Strato, Phanias, and others brought Aristotle’s lectures, lecture notes, their own records, and the recollections of themselves and others to a state fit for publication, thus making the works of Aristotle available to the world. One of the three ethical works in the Aristotelian corpus, the Eudemian Ethics, actually bears Eudemus’ name, but the significance of the title, which is first attested by Atticus Platonicus in the age of the Antonines, is still an open question, complicated by the fact that books IV-VI are identical with books V-VII of the Nicomachean Ethics. At various times it was thought that the treatise was a genuine work of Aristotle dedicated to Eudemus, or that Eudemus was himself its author, or that it was a work of Aristotle edited by Eudemus.
Although the moral teaching of the Eudemian Ethics is fundamentally the same as that of the other ethical treatises, the final book differs in that it holds up as the ideal of “the contemplation of God.” This has led to a picture of the Rhodian philosopher as the “pious Eudemus” which would lose its force if von Arnim is right in detecting the substitution of “God” for “mind” by a Christian interpolator.
Eudemus wrote a Physics, in four books, that covered the same ground as Aristotle’s treatise, the first book corresponding to Aristotle’s I and II, the second to Aristotle’s III and V, the third to Aristotle’s IV, and the fourth to Aristotle’s VI and VIII, which confirms the belief that VII is not genuine. Simplicius used Eudemus’ work extensively in his elucidation of Aristotle; some ninety fragments are gathered together by Wehrli. It is thus possible substantially to reconstruct Eudemus’ treatise, but as it so largely overlaps that of Aristotle it is not necessary to discuss the contents here.
Eudemus made contributions of his own to the Aristotelian logic. He wrote a book - or possibly two separate books - on analytics and the categories and another entitled On Discourse, which seems to have dealt with the same topics as Aristotle’s De interpretatione. That Galen wrote a commentary on it is evidence that it had some vogue in antiquity.
According to Boethius, Theophrastus and Eudemus (in one place “or Eudemus”) added five moods to the four in the first syllogistic figure, and a Greek fragment of unknown authorship adds that they were later made into a fourth figure. The four moods of the first figure are those known since Peter of Spain as Barbara, Celarent, Darii, and Ferio.
The work of Theophrastus and Eudemus on the new moods is bound up with the distinction that they developed between necessary and merely factual premises and conclusions.
It is remarkable that in their development of Aristotle’s logic the names of Theophrastus and Eudemus are so often conjoined. Although there are many references to Theophrastus alone, only one to Eudemus alone is recorded; it may thus rightly be inferred that Theophrastus had the major share in the work. Bochenski supposes that the Organon represents Aristotle’s earlier logical thinking and that in his later lectures he advanced beyond it; and that Theophrastus and Eudemus, who were present at these lectures, separately represent the mature development of Aristotle’s logical thought. The coincidence of their views, he thinks, cannot be explained by chance or close and prolonged collaboration.
From a long passage in Damascius it may be inferred that Eudemus wrote a history of theology that appears to have dealt with the origins of the universe and to have ranged over the views of the Babylonians, Egyptians, and Greeks. A single reference in Proclus establishes that Eudemus wrote one purely mathematical work - On the Angle - in which he took the view that angularity is a quality rather than a quantity (since angularity arises from an inclination of lines, and since both straightness and inclination are qualities, so also must angularity be).
Eudemus is also important for his studies in the history of science. He wrote three works - a history of arithmetic, a history of geometry, and a history of astronomy - which are of capital value for the transmission of the facts about early Greek science. Although like all of Eudemus’ works, they have been lost, it is mainly through the use made of them by later writers that we possess any knowledge of the rise of Greek geometry and astronomy. Eudemus is not known to have had any predecessors in this field, and he may justly be regarded as the father of the history of science, or at the least as sharing the paternity with his fellow Peripatetics Theophrastus, author of Views of the Physicists, and Menon, author of a history of medicine.
Aristotle believed that there were combinations of an apodeictic and an assertoric premise which led to an apodeictic conclusion. For the first figure, he laid down the rule that an apodeictic major and an assertoric minor may lead to an apodeictic conclusion, while the combination of an assertoric major and an apodeictic minor cannot.
According to Alexander of Aphrodisias, the followers of Eudemus and Theophrastus took the opposite view, holding that if either the major or the minor premise is assertoric the conclusion must also be assertoric. Similarly, they held that if either premise is negative the conclusion must also be negative, and if either premise is particular the conclusion must be particular. They summarized their doctrine in the saying that the conclusion must be like the “inferior premise,” or as it was later put into Latin, peiorem semper sequitur conclusio partem.
Another divergence between Aristotle and his two leading pupils arose over problematic syllogisms. For Aristotle, the proposition “That all B should be A is contingent” entails “That no B should be A is contingent”; and “That some B should not be A is contingent,” with related propositions; and the proposition "That no B should be A is contingent” does not imply “That no A should be B is contingent.” According to Alexander, Theophrastus and Eudemus rejected this departure from the general principle that universal negative propositions are simply convertible and particular negative propositions not convertible. They have found a supporter in modern times in H. Maier, but W. D. Ross regards Aristotle as completely justified.