S is wise iff:
1. S has extensive factual and theoretical knowledge.
2. S knows how to live well.
3. S is successful at living well.
4. S has very few unjustified beliefs.
I like the attempt, but I don't think this is promising at all. What strikes me about the discussion leading up to this conclusion is that it leaves out completely what has perhaps been the dominant view of wisdom over the centuries, namely, that wisdom is a disposition to right judgment about the first and most important things. One of the advantages of this description over Ryan's is that it allows you to recognize both domain-general and domain-specific forms of wisdom (depending on which first and most important things are in view). The above definition could only apply to domain-general forms of wisdom, because of #2 and #3, which make it utterly implausible for any domain-specific form. Someone who is wise in a craft is not necessarily someone who knows how to live well, nor are they necessarily successful at living well. Contrast it with, say, Aquinas's account, in which wisdom is a virtue in which we consider rightly the highest causes (clearly a version, and a very influential one, of the dominant view I've mentioned). Aquinas explicitly allows for domain-general forms of wisdom (two kinds!), which in his view consider divine causes, and domain-specific forms of wisdom: "Accordingly he that knows the highest cause in any particular genus, and by its means is able to judge and set in order all the things that belong to that genus, is said to be wise in that genus, for instance in medicine or architecture" (ST 2-2.45.1c; he gives 1 Corinthians 3:10 as an example of this sort of usage).
Another weakness in the article is that it ignores an entire field of contemporary philosophy that deals at great length with issues of wisdom, namely, Sage Philosophy. And, again, this touches on another major current in thought about wisdom through the ages, the relation of wisdom to what we call wisdom traditions -- proverbs, advice, and the like. After all, Socrates may be wise, but so are Okemba Simiyo Chaungo or Paul Mbuya Akoko in their own diverse ways; so are, sometimes and in their own small ways, the old men and women sitting on their front porches in some small town in Mississippi, thinking about what's important in life and passing it down to the younger generation. You don't need extensive factual and theoretical knowledge to be wise; you need the right kind of knowledge. You don't need to have very few unjustified beliefs to be wise; it's possible to be a mixture of wise and foolish, as long as you are so in different ways. Nor, perhaps, do you need to be successful at living well to be wise, even at living well; there is tragic wisdom: wisdom is sometimes found at the end of a long road of failure, after you have missed your chances for living well, and come to see what serious foolishness it all was. Wisdom comes in many forms.