One virtue that I see in people I admire is curiosity. As far as I know, it was not a classical virtue, and its only appearances in the Bible resulted in someone being expelled from the garden or turned into a pillar of salt. What do ethical philosophers have to say about curiosity?

I agree that curiosity is a great virtue, but I disagree that it was not a classical virtue. You are simply looking at the wrong "classics"!

It is no surprise that curiosity is treated with suspicion (at best) in religious works whose whole goal is to get the reader to follow certain dogmas or patterns of thought. Curiosity is the very thing that overturns dogmas and questions all authorities, and those promoting dogmas and authority (usually their own) know this well.

But not all "classical works" were devoted to the promotion and maintenance of special dogmas or authorities. Have a look at ancient Greek philosophy, and see what they say about (and how much they exemplify) this great virtue of curiosity. Specifically, look through a book on the presocratic philosophers and ask yourself how curious they must have been, to come up with such theories to explain the world around them. Read Plato's Apology and find out how Socrates dedicated (and ultimately forfeited) his life in pursuit of his curiosity. Read Plato's Symposium and Phaedrus in which the curiosity that drives philosophy is characterized as powered by Eros, the most profound desire we experience. Have a look at Aristotle's Metaphysics I.2, in which Aristotle proclaims that "philosophy begins in wonder."

One of the best things about curiosity, I think--and what all of the ancient Greeks understood about it, often quite explicitly--is that it consists, in part, in the recognition of one's own ignorance. I wouldn't be curious about something if I already thought I knew everything I need to know about it. When Aristotle says that philosophy begins in wonder, he means that philosophy begins with a sense that there is something to wonder about, which we don't do with things we presume ourselves already to know completely. This is why religious texts do not generally promote curiosity--because they are peddling their doctrines as already known and thus not to be questioned. But philosophy (including ancient Greek philosophy) begins in wonder-- in curiosity--which involves a recognition that we do not know. And because we do not, but want to, know, we begin to ask curious questions.

And some of us still wonder, just as Thales (the first Greek philosopher) did, just as Socrates and Plato did, and just as Aristotle did. Some of us are still curious, and we promote this great and deeply human (even wonder-ful) virtue every chance we get.

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