deny the myth of the horse-centaurs, giving us the horse-centaur as an example of non-existence.  Now we could give many other examples of each 163 of the antitheses mentioned above, but for a brief argument, these are sufficient.  Since, however, such anomaly of things is shown by this Trope also, we shall not be able to say what objects are by nature, but only what each thing appears to be like, according to this or that school, or this or that law, or this or that custom, or according to each of the other conditions.  Therefore, by this Trope also, we must suspend our judgment in regard to the nature of external objects.  Thus we arrive at [Greek:  epoche] through the ten Tropes.

CHAPTER XV.

The Five Tropes.

The later Sceptics, however, teach the following five Tropes 164 of [Greek:  epoche]:  first, the one based upon contradiction; second, the regressus in infinitum; third, relation; fourth, the hypothetical; fifth, the circulus in probando.  The one 165 based upon contradiction is the one from which we find, that in reference to the thing put before us for investigation, a position has been developed which is impossible to be judged, either practically, or theoretically, and therefore, as we are not able to either accept or reject anything, we end in suspending the judgment.  The one based upon the regressus 166 in infinitum is that in which we say that the proof brought forward for the thing set before us calls for another proof, and that one another, and so on to infinity, so that, not having anything from which to begin the reasoning, the suspension of judgment follows.  The one based upon relation, as we have 167 said before, is that one in which the object appears of this kind or that kind, as related to the judge and to the things regarded together with it, but we suspend our judgment as to what it is in reality.  The one based upon hypothesis is 168 illustrated by the Dogmatics, when in the regressus in infinitum they begin from something that they do not found on reason, but which they simply take for granted without proof.  The Trope, circulus in probando, arises when the thing 169 which ought to prove the thing sought for, needs to be sustained by the thing sought for, and as we are unable to take the one for the proof of the other, we suspend our judgment in regard to both.  Now we shall briefly show that it is possible to refer every thing under investigation to one or another of these Tropes, as follows:  the thing before us is either sensible or intellectual; difference of opinion exists, however, as to what it is in itself, for some say that only the things of sense 170 are true, others, only those belonging to the understanding, and others say that some things of sense, and some of thought, are true.  Now, will it be said that this difference of opinion can