"People are usually characterized as intelligent based on an incorrect usage of that word. It is not those who have studied the sayings and writings of ancient wise men that are intelligent. Rather, it is those who have an intelligent rational soul, who are capable of distinguishing good from evil, who avoid everything that is evil and bad for the soul, and who wisely show concern for the good and useful, and while doing so, render great thanks to God. They alone should actually be called intelligent people."
-- St. Anthony the Great
I've stolen this from Father Joseph at our church, because it's too good not to share. It's like a mini-version of The Proverbs of Solomon, isn't it? True Wisdom is embodied in Christ Himself (hint: that's why "Wisdom" is capitalized in The Proverbs - it's just another way of speaking of Christ) and therefore those that seek after Him can be called wise. In Orthodoxy there is no division of the heart and the head, the way there is in the West, where one's emotions live in the heart and one's rational thoughts come from the head. Orthodox know that no such division can really be made, so one who is filled with true spiritual intelligence will act and think accordingly. Here's an even better explanation than mine: check it out.
The Icon of St. Anthony the Great is from this page.