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.