Wisdom Of The One is a relatively-common term, usually used to refer to a system similar to Wisdom Of The Mod. (There are some technicalities which keep the two from being total synonyms, but they are pretty similar terms all the same. Technical definitions given here.) However, Wisdom Of The One in this case also applies to Wisdom as a mafia player. In my experience with him, Wisdom tends to--for better or for worse--place a disproportionately high level of trust in his own base instincts. He basically trusts his own gut, his own reads, to have a higher level of accuracy than those of others.
Thus...Wisdom Of The One: "I know best", but not with a connotation of negativity. It's just a part of him.