MIT now posted a lot of their course materials as freely available open educational resources (OER) at their site here. This is a great idea I think this will eventually change the world as the world is getting flatter and flatter.
Naturally I glance through the Master Course List and looked for something I may have interest in. Glad to see Linguistics and Philosophy are housed under one section. I'm certainly not capable of knowing why but I read that very early philosophers found answers and teach pupils simply by talking without much documentation of their thoughts.
Bookmark this OPENCOURSEWARE CONSORTIUM site as well if you are keen to be self-taught.