Sextus Empiricus Pyrrhoniae Hypotyposes 1.28.206

[206] In a preliminary outline it will be sufficient to have explained the expressions now set forth, especially since it is possible to explain the rest by deductions from the foregoing. For, in regard to all the Sceptic expressions, we must grasp first the fact that we make no positive assertion respecting their absolute truth, since we say that they may possibly be confuted by themselves, seeing that they themselves are included in the things to which their doubt applies, just as aperient drugs do not merely eliminate the humours from the body, but also expel themselves along with the humours.