but not between others. For if there is something between genera, there is also between species, and if between species, likewise between genera, as in virtue and vice, and justice and injustice, for there is something between each of these. To this it may be objected, that there is nothing between health and disease, but that there is something between evil and good, or whether there is something between both the species and genera, yet not similarly, but between the one negatively, and between the other as a subject, for it is probable that something similarly intervenes between both, as between virtue and vice, justice and injustice, for there are intermediates between both, according to negation. Further, when there is not a contrary to genus, we must observe not only whether the contrary is in the same genus, but also whether the medium is, for the media are in the same genus as the extremes, as, for instance, in white and black, for colour is both the genus of these, and of all intermediate colours. An objection may lie, that defect and excess, are in the same genus, (as both are in what is evil,) but the moderate, which is a medium between these, is not in what is evil, but in what is good. Notice too, whether the genus is contrary to a certain thing, but the species to nothing, as if the genus is contrary to a certain thing, the species is also, as virtue and vice, justice and injustice. Likewise, to one who considers other things, such a thing would appear evident. There is an objection in health and disease, for health simply, is contrary to disease, yet a certain disease, being a species of disease, is not contrary to any thing, e. g. a fever and ophthalmia, and every other (disease).
The subverter then, must pay attention in so many respects, for if what have been mentioned are not inherent, the thing assigned is evidently not a genus, but the confirmer (must regard them) triply: first, whether the contrary to species is in the before-named genus, when there is not a contrary to the genus, for if the contrary is in this, it is evident that the proposition is also: next, whether the medium is in the above-named genus, as in what the media are the ex-
