I don't think that the 'Skeptoid' site gives a definitive definition of 'skepticism'. It's just a blog produced by some very opinionated guy. His error seem to me to be confusion of 'skepticism' with something like 'sound reasoning'. (Sciforums participants often foolishly use the word 'science' to mean the same thing.) In everyday usage, 'skepticism' means something like 'doubt' or 'incredulity'. 'I'm skeptical about that' means 'I'm doubtful about that'. Philosophers understand 'skepticism' in a more technical and historical way. The ancient Greek skeptics used the word to refer to the idea that knowledge is impossible, usually associated with the idea that not being attached to views brings emotional stability, imperturbability and happiness. (That idea may have been influenced by early Buddhism.) But ultimately it leads to a profound anti-intellectualism. The ancient skeptics divided into two schools, known by philosophers today as Pyhrronian and Academic. Pyhrronian skepticism is the better known of the two, since we still have the writings of one prominent Roman era Pyhrronian, Sextus Empiricus. Pyhrronianism was the idea that equally strong arguments can be brought for and against any proposition, so that there is no good reason to believe one thing over another. Academic skepticism (called 'academic' because it dominated Plato's Academy for a time after Plato's death) isn't as clear, but it seemingly evolved into the idea that nothing is certain, though some beliefs might be more plausible than others. The writings of the skeptics were lost in the Latin west during the Middle Ages. But during the Renaissance, the writings of Sextus Empiricus were rediscovered and they caused an intellectual revolution. Skeptical arguments became the rage. Philosophers such as Descartes made it their job to combat skepticism. Theologians, both Catholic and Protestant, employed skepticism in the argument that since nothing can be known, humans must proceed by faith. David Hume, the prototypical British empiricist and seemingly an atheist, argued for what he called "mitigated skepticism", the idea that while our confidence in memory, induction and the uniformity of nature isn't well-founded or entirely certain, we are predetermined by nature (today we would cite evolution) to think in those ways. To some extent, skepticism is what shapes the agenda of epistemology (the theory of knowledge) even today. It's what motivates those 'brain in a vat' arguments. As for me, I consider myself a 'fallibilist' (a word coined by Charles Peirce I believe) which I take to be something akin to academic skepticism as I characterized it above. It's the idea that 'true' and false' are intellectual ideals, while in real life all of our beliefs have some degree of uncertainty. (Belief X might seem to probably be true, but some possibility remains that it could be false.) No matter what the belief (even seeming logical/mathematical certainties) we might conceivably be wrong. Yes. I think that it's important to recognize that. Yes. I couldn't agree more. Science isn't sacred (it's just a human intellectual practice) and it shouldn't be immune from questions and from skeptical examination. That's what the philosophy of science should be doing. When scientists claim to know something or to have discovered something, the philosophers of science need to look closely at that the scientists actually did, at how they did it (logically speaking) and at what kind of initial methodological and metaphysical assumptions went into it.