(i) The one based upon discord.
 (ii) The regressus in infinitum.
(iii) Relation.
 (iv) The hypothetical.
  (v) The circulus in probando.

Two of these are taken from the old list, the first and the third, and Sextus says that the five Tropes are intended to supplement the ten Tropes, and to show the audacity of the Dogmatics in a variety of ways.[6] The order of these Tropes is the same with Diogenes as with Sextus, but the definitions of them differ sufficiently to show that the two authors took their material from different sources.  According to the first one everything in question is either sensible or intellectual, and in attempting to judge it either in life, practically, or “among philosophers,” a position is developed from which it is impossible to reach a conclusion.[7] According to the second, every proof requires another proof, and so on to infinity, and there is no standpoint from which to begin the reasoning.[8] According to the third, all perceptions are relative, as the object is colored by the condition of the judge, and the influence of other things around it.[9] According to the fourth, it is impossible to escape from the regressus in infinitum by making a hypothesis the starting point, as the Dogmatics attempt to do.[10] And the fifth, or the circulus in probando, arises when that which should be the proof needs to be sustained by the thing to be proved.

    [1] Hyp. I. 164.

    [2] Diog.  IX. 11, 88.

    [3] Diog.  IX. 11, 106.

    [4] Diog.  IX. 12, 115-116.

    [5] Compare Natorp. Op. cit. p. 302.

    [6] Hyp. I. 177.

    [7] Hyp. I. 165.

    [8] Hyp. I. 166.

    [9] Hyp. I. 167.

    [10] Hyp. I. 168.

Sextus claims that all things can be included in these Tropes, whether sensible or intellectual.[1] For whether, as some say, only the things of sense are true, or as others claim, only those of the understanding, or as still others contend, some things both of sense and understanding are true, a discord must arise that is impossible to be judged, for it cannot be judged by the sensible, nor by the intellectual, for the things of the intellect themselves require a proof; accordingly, the result of all reasoning must be either hypothetical, or fall into the regressus in infinitum or the circulus in probando.[2] The reference above to some who say that only the things of sense are true, is to Epicurus and Protagoras; to some that only the things of thought are true, to Democritus and Plato; and to those that claimed some of both to be true, to the Stoics and the Peripatetics.[3] The three new Tropes added by Agrippa have nothing to do with sense-perception, but bear entirely upon the possibility of reasoning, as demanded by the science of logic, in contrast to the earlier ones which related