Book 2 of Aristotle's Metaphysics, known as Alpha Elatton (little a) in contrast to the much longer Book 1, Alpha Meizon (Big A), is an
anomalous work. A long central chapter that argues against the
possibility of infinite causes is framed by two short chapters that
have the appearance of introductory statements on methodology,
either that of metaphysics (ch. 1) or of physics (ch. 3). The fact that
in some MSS the book opens with a dependent clause (see 138,24-8
and n. 11), and that the ancient editors of Aristotle's works
identified Book 2 by the same letter of the alphabet as that assigned
to Book 1, is evidence that in antiquity the two books were regarded
as parts of the same treatise.