I suspect that O’Reilly isn’t the only one who misunderstands what the term ‘philosophy’ actually means. It’s likely that a lot of folks cannot explain the difference between a philosophy and a religion (Christianity is most assuredly the latter, a fact that O’Reilly later concedes). Roberto Ruiz, who blogs at Philosophy Monkey, wrote the following post defining what philosophy is, and what it isn’t.
Unfortunately, the word philosophy is used, misused and abused by all kinds of people. For some, like the local drunk at your nearest bar, for instance, it means the semi-coherent and misogynistic ramblings about the “deep truths” he has “discovered” through dozens of failed relationships, and that he can’t help but share with you. For others, it means some sort of “deep” motto, like “believe in yourself.” A slightly more respectable version still is that of a worldview: a set of ideas by which you lead your life, and which, with any luck, are not incompatible with each other.
But for philosophers, philosophy is not a thing... it’s an activity: it is the pursuit of wisdom (the good and the true) by means of rational conceptual analysis, by rigorous and systematic observation, by synthesizing the very best knowledge that we acquire from the sciences, by subjecting claims to rational scrutiny, by questioning what others take for granted, and by developing the existential courage to confront the harshness of reality head-on without having to delude ourselves with comforting beliefs and illusions. Philosophy is something we do, not something we “have”.
Whatever its merits, however, religion is not that. In philosophy, we investigate to find answers, and we go where the evidence takes us. In religion, you start with your preconceived belief first, and then look for ways to back it up later. Philosophy is inquiry; religion is rationalization.
Religion may contain philosophy, but philosophy doesn’t require religion. In fact, religion is often the antithesis of philosophy, with its tendency to favour dogma and orthodoxy over freedom of thought and robust skepticism.