I just watched a really interesting movie on Slavoj Žižek, a Slovenian philosopher/sociologist operating with a sort of Marxist/Lacanian method. While perhaps ultimately frustrating, his work seems to serve as an helpful analysis of why we philosophize, ie. what it means for us to say such-and-such. I won't attempt to define him anymore broadly than that in a blog post, but suffice it to say, he's quite interesting and you should check out Zizek! the movie. There's also a helpful write up in Books & Culture if you want an introduction from a Christian perspective to his work. Here is a quote from that review that I liked:

"For this "fighting atheist" it is not, of course, so much the truth of what Christians believe but the world-altering power of the Christian imagination that attracts him. What Zizek sees is precisely what the comfortable Western Church might be most in need of recovering: an appreciation for the explosive nature of the Christian Gospel and how it calls forth an alternative or counter way of life to the standard operating procedures of the world." -----Ashley Woodiwiss