Sextus Empiricus Pyrrhoniae Hypotyposes 2.13.162

[162] And we deal in like manner with the fourth non- demonstrable argument and the fifth. For either it is pre-evident or it is non-evident that in the disjunctive premiss one clause is true, the other false, in complete contradiction, as the disjunctive proclaims. And if this is non-evident, we shall not grant the disjunctive; but if it is pre-evident, if one of its clauses be affirmed it is apparent that the other is not true, and if one is negated it is pre-evident that the other is true, so that it is sufficient to frame the argument thus—‟It is day, therefore it is not night,” or ‟It is not day, therefore it is night;” and the disjunctive premiss is redundant.