As you read this blog, you're probably working under the assumption that some guy, a so-called philosophy monkey, wrote this entry. You may not know who he is, but you're pretty sure he's not you. You probably think this because you're not aware of writing for this blog, so if you're not aware of something being done, then it's not you who did it. Of course, if we allow for the possibility that this is all just a dream you're having, or even a dream within a dream (your 'waking up' this morning proves nothing), then all bets are off...
Welcome to the skeptical problem of solipsism (or at least one version of it): the idea that it may be impossible to tell the difference between a real mind-independent external world (what you're probably used to believing) vs. a completely realistic dream, or a hallucination, or a situation in which you are just a brain in a vat fed information by a scientist just messing with you through a super computer, or a world in which all that exists is you and your ideas and perceptions, or being stuck in something like The Matrix.
Can we have knowledge of a mind-independent external reality that's really "out there"? In the fourth lecture in this series, Professor Millican explores the history of this problem, starting with Descartes' skeptical arguments, as well as some of the possible solutions offered over the years, especially G.E. Moore's Defense of Common Sense.
Click here to see the course slides