Book 5
1. In regard to Justice1 and Injustice, we have to enquire what sort of actions precisely they are concerned with, in what sense Justice is the observance of a mean, and what are the extremes between which that which is just is a mean. 1. [2] Our enquiry may follow the same procedure as our preceding investigations.1. [3]Now we observe that everybody means by Justice that moral disposition which renders men apt to do just things, and which causes them to act justly and to wish what is just; and similarly by Injustice that disposition which makes men act unjustly and wish what is unjust. Let us then assume this definition to start with as broadly correct.1. [4]
The fact is that it is not the same with dispositions as with sciences and faculties. It seems that the same faculty or science deals with opposite things2; but a disposition or condition which produces a certain result does not also produce the opposite results; for example, health does not give rise to unhealthy actions, but only to healthy ones: healthy walking means walking as a healthy man would walk.3 1. [5]
Hence4 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,