1.1.14

Here it seemed to be used in the context of a person making a conscious choice to follow sophistic teachings because he believed them--the opposite example presented being the example of a rhetorician who's choice to follow rhetorical practices was based on ability. (At least this is what I gathered from it! If so, the contrast between choice and ability between sophists and rhetoricians is interesting!)

1.8.6

In this example proairesis is used as a decision of the audience to believe a speaker because of his character, or as an illustration of how a person's behavior defines his character

3.16.8

Here character is defined again by choice of actions. Emphasis on choice. Aristotle presents an example of math having no moral character because there is no choice of action when performing it, while rhetoricians do have ethical choices of how they use their skills. (character linked to rhetoric?)

In a nutshell then, I would have to sum up this definition to contain two parts:

1. a deliberate decision

2. decision made on basis of evaluation of character