Book 5
5
HenceBecause a faculty or science is the same for opposite things. sometimes the nature of one of two opposite dispositions is inferred from the other, sometimes dispositions are known from the things in which they are found; for instance, if we know what good bodily condition is, we know from this what bad condition is as well, but we also know what good condition is from bodies in good condition, and know what bodies are in good condition from knowing what good condition is. Thus, supposing good condition is firmness of flesh, bad condition must be flabbiness of flesh, and a diet productive of good conditionLiterally that which has to do with good condition: the word here slightly shifts its meaning, for just above it meant that which is in good condition. must be a diet producing firmness of flesh.
6
Also, if one of two correlative groups of words is used in several senses, it follows as a rule that the other is used in several senses too: for example, if just has more than one meaning, so also has unjust and Injustice.
