Character traits are 1) dispositions or habit-like tendencies that are deeply entrenched or engrained.
They have been referred to as second nature--"first nature" referring to tendencies with which we are born.
I have added some lecture notes from the Fall 2002 lectures on virtue ethics. There may be some overlap between the two parts of this webpage, but materials from the one section may add to your understanding of the other.
Virtue ethics is an approach that deemphasizes rules, consequences and particular acts and places the focus on the kind of person who is acting.
For instance, the ancient Greeks had a place for the virtue of pride (an appropriate sense of one's honor), while medieval Christian monks thought humility more important.
The ancient Greeks had a moral ideal of seriousness, which could be expressed in religious, philosophical, or ethical activity, but not so easily in physical production; early modern thinkers, however, recognize a virtue of industriousness, which tend to be expressed in activity related to production, to subduing the physical environment.An act or choice is morally right if, in carrying out the act, one exercises, exhibits or develops a morally virtuous character.It is morally wrong to the extent that by makiing the choice or doing the act one exercises, exhibits or develops a morally vicious character.The virtue of courage, for example, lies between the vices of rashness and cowardice.The coward has too much fear, or fear when he should have none.The virtuous person will get angry when she should, but not excessively and not contrary to reason.Aristotle calls the virtue of appropriate anger mildness or gentleness.Some students would prefer not to study my introductions to philosophical issues and approaches but learn directly from the source.I have no objection to this procedure if it works for you.Others may wish to consult the source before or after hearing or reading my introductions.Here is the horse's mouth himself, Aristotle, discussing the nature of moral virtue, in Book II of the Nicomachean Ethics.