rence in the order of the
Tropes shows, also, that the order was not considered a matter
of great importance. There is a marked contrast in the spirit of
the two presentations of the Tropes given by Sextus and
Diogenes. The former gives them not only as an orator, but as
one who feels that he is defending his own cause, and the school
of which he is the leader, against mortal enemies, while
Diogenes relates them as an historian.

[1] _Hyp._ I. 36.

[2] _Adv. Math._ VII. 345.

[3] _Hyp._ I. 38.

[4] Diog. IX. 11, 87.

[5] Diog. IX. 11, 87.

Pappenheim tries to prove[1] that Aenesidemus originally gave
only nine Tropes in his _Pyrrhonean Hypotyposes_, as Aristocles
mentions only nine in referring to the Tropes of Aenesidemus,
and that the tenth was added later. Had this been the case,
however, the fact would surely have been mentioned either by
Diogenes or Sextus, who both refer to the ten Tropes of
Aenesidemus.

The Tropes claim to prove that the character of phenomena is so
relative and changeable, that certain knowledge cannot be based
upon them, and as we have shown, there is no other criterion of
knowledge for the Sceptic than phenomena.[2] All of the Tropes,
except the tenth, are connected with sense-perception, and
relate to the difference of the results obtained through the
senses under different circumstances. They may be divided into
two classes, _i.e._, those based upon differences of our
physical organism, and those based upon external differences. To
the first class belong the first, second, third and fourth; to
the second class, the fifth, sixth, seventh and eighth, and also
the ninth. The eighth, or that of relation, is applied
objectively both by Sextus and Diogenes in their treatment of
the Tropes, and is not used for objects of thought alone, but
principally to show the relation of outward objects to each
other. The tenth is the only one which has a moral significance,
and it has also a higher subjective value than the others; it
takes its arguments from an entirely different sphere of
thought, and deals with metaphysical and religious
contradictions in opinion, and with the question of good and
evil. That this Trope is one of the oldest, we know from its
distinct mention in connection with the foundation theories of
Pyrrho, by Diogenes.[3] In treating of the subjective reasons
for doubt as to the character of external reality, the Sceptics
were very near the denial of a