such and such.
Quality is a term that is used in many senses. One sort of quality
let us call 'habit' or 'disposition'. Habit differs from disposition
in being more lasting and more firmly established. The various kinds
of knowledge and of virtue are habits, for knowledge, even when
acquired only in a moderate degree, is, it is agreed, abiding in its
character and difficult to displace, unless some great mental upheaval
takes place, through disease or any such cause. The virtues, also,
such as justice, self-restraint, and so on, are not easily dislodged
or dismissed, so as to give place to vice.
By a disposition, on the other hand, we mean a condition that is
easily changed and quickly gives place to its opposite. Thus, heat,
cold, disease, health, and so on are dispositions. For a man is
disposed in one way or another with reference to these, but quickly
changes, becoming cold instead of warm, ill instead of well. So it
is with all other dispositions also, unless through lapse of time a
disposition has itself become inveterate and almost impossible to
dislodge: in which case we should perhaps go so far as to call it a
It is evident that men incline to call those conditions habits which
are of a more or less permanent type and difficult to displace; for
those who are not retentive of knowledge, but volatile, are not said
to have such and such a 'habit' as regards knowledge, yet they are
disposed, we may say, either better or worse, towards knowledge.
Thus habit differs from disposition in this, that while the latter
in ephemeral, the former is permanent and difficult to alter.
Habits are at the same time dispositions, but dispositions are not
necessarily habits. For those who have some specific habit may be said
also, in virtue of that habit, to be thus or thus disposed; but
those who are disposed in some specific way have not in all cases
the corresponding habit.
Another sort of quality is that in virtue of which, for example,