Some of Aristotle's philosophical writings then are earlier than others;
because they show more Platonic influence, and are more rudimentary;
e.g. the _Categories_ earlier than some parts of the _Metaphysics_,
because under the influence of Platonic forms it talks of inherent
attributes, and allows secondary substances which are universal; the _De
Interpretatione_ earlier than the _Analytics_, because in it the
Platonic analysis of the sentence into noun and verb is retained for the
proposition; the _Eudemian Ethics_ and the _Magna Moralia_ earlier than
the _Nicomachean Ethics_, because they are rudimentary sketches of it,
and the one written rather in the theological spirit, the other rather
in the dialectical style, of Plato; and the _Rhetoric to Alexander_
earlier than the _Rhetoric_, because it contains a rudimentary theory of
the rational evidences afterwards developed into a logic of rhetoric in
the _Rhetoric_ and _Analytics_.
It is tempting to think that we can carry out the chronological order of
the philosophical writings in detail. But in the gradual process of
composition, by which a work once begun was kept going with the rest,
although a work such as the _Politics_ (begun in 357) was begun early,
and some works more rudimentary came earlier than others, the general
body of writings was so kept together in Aristotle's library, and so
simultaneously elaborated and consolidated into a system that it soon
becomes impossible to put one before another.