that was set free by Alexander's death, and he died in Euboea the following year. We know as little
about him personally as we do about Plato, and in his case the 'biographical' tradition is even more
untrustworthy; it has been infiltrated by hostile and interested sources. We do get the impression of an
attractive personality from his will, preserved in the Life by Diogenes Laertius.
Aristotle wrote a great deal, and like Plato produced many works in dialogue form for the general public.
These survive only in fragments, and what we read as the 'Corpus Aristotelicum' consists of lectures and
notes on courses within his school. Later these were grouped by an editor into the books -we now read
as the Metaphysics, Physics, Organon, and so on; but there are many signs that these unities are
factitious. We find different treatments of the same issues; puzzling cross-references; later insertions;
and a very uneven level of stylistic finish. The argument is usually very dense, and -was clearly used as
a basis for discussion; the reader can seldom coast along, and has to pause and work slowly through the
thought. Aristotle has been found defeating by those who look for purely literary appeal; but he is an
exciting and rewarding author if one has the right expectations of hard work and co-operation.
Unlike Plato, Aristotle never leaves the tradition in which study of the natural world, and its systematic
explanation, are normal philosophical tasks. The Physics, the De generatione et corruptione and the De
caelo explain natural events in terms of highly theoretical principles, and give an account of the structure
and physical constitution of the universe. But Aristotle's energetic appetite for explanation does not stop
there; it conies down to more mundane levels. In the Meteorologica, for example, he produces an
(understandably primitive) geology, meteorology, and chemistry: in the De sensu, ch. 3, we find a theory
about colours. But it is living things that absorb Aristotle's interest to the greatest extent. The De anima
and Parva naturalia, essays which create the science of the psychology of living things, are followed by
massive studies of various aspects of the animals (including humans): the De generatione animalium
discusses their reproduction, the De motu and De incessu animalium their modes of movement, the De
partibus animalium their parts and structure. The Historia animalium is a record of animals' behaviour
and habits, a record that must have been compiled in collaboration with others and that, although often
wrong and sometimes credulous, is a famous historical monument of empirical science. Aristotle was
the first biologist and is still respected by biologists. Instead of haphazardly using available reports, he
made great efforts to observe many creatures for himself, seeking data and observations relevant to his
enquiries. It is characteristic of Aristotle to devote energy both to theoretical physics and to empirical
biology, valuing both with a width of vision impossible to recapture today.
Of all beings naturally composed, some are ungenerated and imperishable for the whole of eternity, but
others are subject to coming-to-be and perishing. It has come about that in relation to the former, which
possess value-indeed divinity-the studies we can make are less, because both the starting-points of the
inquiry and the things we long to know about present extremely few appearances to observation. We are
better equipped to acquire knowledge about the perishable plants and animals because they grow beside
us ... Both studies have their attractions. Though we grasp only a little of the former, we gain more
pleasure than from everything around us ... (but because the latter) are closer to us and belong more to
our nature, they have their own compensations in comparison with the philosophy concerned with the
divine things ... Even in the study of animals unattractive to the senses, the nature that fashioned them
offers immeasurable pleasures ... to those who can learn the causes and are naturally lovers of wisdom ...