I asked atheists two questions in the comments on my previous post in this series, and I think it is worth bringing them up front:
a) Is wisdom something worth pursuing?
b) If so, how do you pursue it?
I see these questions as a way to swiftly distinguish the humourless from the sophisticated atheist. That is, the humourless will respond to a) with some sort of denial or equivocation, asserting or implying that wisdom doesn't exist (or can be reductively made equivalent to "just" personal preference). In contrast, the sophisticated atheist will not only answer a) positively but will be interested in exploring the questions that arise from any possible answer to b). (To my mind, this is where the conversations become most interesting - sophisticated atheists will criticise Christianity on the basis of how well it actually functions to cultivate wisdom. This gives rise to criticisms that Christians must listen to.)
So what do I mean by wisdom? I would say something like: wisdom is the capacity to act and choose in a way that enables human flourishing. Which is very Aristotelean: I have in mind the virtue of phronesis, right judgement. Now there is a question to be pursued about what constitutes human flourishing (eudaimonia) but that need not detain us too long. I would argue that the different wisdom traditions embody different answers to that question and what I most want to pay attention to is the difference between all of the different wisdom traditions and the perspective that treats all wisdom traditions as irrational and not worth pursuing. The sophisticated atheist can engage in conversations about what actually does foster human flourishing because the essential premise is accepted (ie a positive answer to my first question). I would then want to go along the lines MacIntyre sketched out in "Whose Justice? Which Rationality?" and ask questions about the traditions as a whole.
So what is wrong with reducing wisdom to personal preference, that it's simply a question of what different people like? Well, lots of things, but let's begin with the idea that wisdom is something that can be acquired; that it is something which is centrally involved in the formation of a character; and that it therefore cannot be reduced to personal preference for the simple reason that the 'personal' element is what is changeable. Wisdom is all about enabling a person to develop their character, in the sense of acquiring virtues (eg honesty, courage, prudence etc) that will turn them into something different - a more honest, courageous and prudent person.
As I understand wisdom, then, it is not dependent upon being placed in a theistic tradition (which is presumably what the on-line dictionaries were drawing on when considering scientia and sapientia). Buddhism, for example, is perfectly capable of generating wise people! You could say that what I want to insist upon, in distinguishing between atheisms, is that some forms of atheism discard too much; that the reasons why they discard too much are open to question; and that there is no necessity to reject wisdom whilst rejecting theism. However, such atheisms are normally most accurately described by the answers given to b), rather than the basically content-free 'atheist' label.