e reasons of all phenomena 218
are present in matter, so that matter can be all that it appears
to be to all men as far as its power is concerned. Men, however,
apprehend differently at different times, according to the
different conditions that they are in; for he that is in a
natural condition will apprehend those qualities in matter that
can appear to those who are in a natural condition, while on 219
the contrary, those who are in an unnatural condition will
apprehend those qualities that can appear to the abnormal.
Furthermore, the same reasoning would hold true in regard to
differences in age, to sleeping and waking, and each of the
other different conditions. Therefore man becomes the criterion
of things that are, for all things that appear to men exist for
men, and those things that do not appear to any one among men do
not exist. We see that he dogmatises in saying that matter is
fluid, and also in saying that the reasons for all phenomena
have their foundation in matter, while these things are unknown,
and to us are things regarding which we suspend our judgment.

CHAPTER XXXIII.

_In what does Scepticism differ from the Academic
Philosophy?_

Some say further that the Academic philosophy is the same as 220
Scepticism, therefore it seems appropriate to me to treat of
that also. There have been, as the most say, three
Academies--the most ancient one, that of Plato and his
followers; the second and middle one, that of Arcesilaus and his
followers, Arcesilaus being the pupil of Polemo; the third and
new Academy, that of Carneades and Clitomachus and their
followers; some add also a fourth, that of Philo and Charmides,
and their followers; and some count even a fifth, that of
Antiochus and his followers. Beginning then from the old
Academy, let us consider the difference between the schools of
philosophy mentioned. Now some have said that Plato was a 221
Dogmatic, others that he was a Sceptic, and others that he was
in some things a Sceptic and in some things a Dogmatic. For in
the fencing dialogues, where Socrates is introduced as either
making sport of someone or contending against the Sophists,
Plato has, they say, a fencing and sceptical character, but he
is dogmatic when he expresses himself seriously, either through
Socrates or Timaeus or any such person. In regard to those 222
who say that he is a Dogmatic, or a Dogmatic in some things and
a Sceptic in other