With matters of etiquette, such as which hand to use for the fork, or matters of personal preference, such as which wrist to use for one's watch, I don't think "Why?" questions are intellectually substantial enough to be worth asking more than once or twice. But philosophical and scientific questions are intellectually much more substantial, much deeper. There it makes excellent sense to keep asking "Why?" questions for as long as those questions remain well-posed. You're right that we don't want a loop -- a circle -- of "Why?" questions, because in that case a question reappears after it has already been adequately answered. But a loop is different from a regress of questions, which may be finitely long or indefinitely long. On whether an indefinitely long regress is always something to avoid, see this SEP entry .

I think that you and those you see as your opponents may simply be talking past each other. You define consciousness so that being conscious logically guarantees being aware of your surroundings. In arguments about external-world skepticism, consciousness has traditionally been given a weaker definition, a definition that doesn't logically guarantee being aware of your surroundings. In the classic evil demon scenario, your conscious mental states are caused by the evil demon and not by your surroundings (not even indirectly). You're conscious -- that is, you're not in the midst of an experiential blank -- but your conscious states are unreliable indicators of your surroundings. Sometimes the term "perception" is used to distinguish conscious states that reliably represent the environment from conscious states that represent it unreliably . I hasten to add that it takes a lot of argument to get from (1) the admission that consciousness can be inaccurate to (2) the conclusion that we never achieve...

I think the wording of your question contains the answer. You define an objective view as a view that is true independently of human opinions. A view can satisfy that definition even if every view is someone's view. The fact that no view can be held without being held by someone doesn't imply that no view can be true independently of human opinions. Take a simple example: If your view is that elephants are bigger than mice, your view can be true independently of human opinions even though it's held by a human and formed on the basis of human perception. It's a separate issue how you know that elephants are bigger than mice. But the objective truth of the view isn't threatened merely by its being your view.

The external-world skeptic purports to show that I can't know any external-world proposition P. How about this response? 1. Conceptual analysis reveals that knowledge is nothing more than reliably produced true belief, where reliability falls far short of logical infallibility. 2. If knowledge is nothing more than reliably produced true belief, then the skeptic's sensitivity condition on knowledge is false: I can have a reliably produced true belief that P, and hence knowledge that P, even if I would falsely believe that P if I were being deceived by an evil demon. (Analogy: My gas-engine car can be reliable even if it wouldn't work at all if it were on the airless surface of the moon.) 3. In particular, I can have a reliably produced true belief, and hence knowledge, that I'm not being deceived by an evil demon even if, were I being deceived by an evil demon, my belief that I'm not being deceived would not be reliably produced. The skeptic then predictably asks: "But how do you know...

It's not clear to me what you're asking, but I'll do my best. Given a particular conclusion, we can, normally, trace it back to the very basic premises that constitute it. I doubt we can do that without seeing the conclusion in the context of the actual premises used to derive it. The conclusion Socrates is mortal follows from the premises All men are mortal and Socrates is a man , but it also follows from the premises All primates are mortal and Socrates is a primate . So which pair of premises are "the very basic premises" for that conclusion? Outside of the actual argument context, the question has no answer. I don't know what you mean by "the root of a conclusion," but you seem to be suggesting that any knowledge is impure if it depends on -- or if it was acquired using -- any reasoning at all. Perhaps the term inferential would be a better label for such knowledge. On this view, even if I have direct knowledge that I am in pain (when I am), I have only...

Three points: 1. It's not clear that the project of eliminating all of our presuppositions even makes sense. For instance: Could we coherently try to eliminate our presupposition that eliminating a given presupposition is inconsistent with keeping that presupposition? I can't see how. Indeed, Descartes himself seems ambivalent about the possibility, or desirability, of eliminating all of our presuppositions, because in his work he frequently appeals to unargued-for principles that, he says, "the natural light" simply shows us must be true. 2. Your argument for the claim that "Answering skepticism should be [a] priority in philosophical research" relies on this premise: Descartes was correct to claim that no belief is justified if it can be subjected to any doubt. Most philosophers, now and in Descartes's time, would reject that condition on justified belief as far too strict. They would challenge Descartes to derive that strict condition from a recognizable concept of justified belief, rather...

It needn't. Like Descartes, you might try to demonstrate a priori that you possess perceptual (i.e., external-world) knowledge. Your demonstration needn't presume perceptual knowledge in the course of demonstrating that you possess perceptual knowledge. Therefore, your demonstration needn't beg the question of whether you have perceptual knowledge in the first place. Most philosophers, I think, regard all such demonstrations (including Descartes's) as failures, but I don't see any reason to think that all such demonstrations must fail because they beg the question. Consider a more interesting case. Suppose I analyze knowledge as true belief produced by a reliable mechanism , i.e., a mechanism that yields far more true than false beliefs in the conditions in which it's typically used. A skeptic then challenges me to show that some perceptual belief I regard as knowledge, such as my belief that I have hands, was in fact produced by a reliable mechanism. In response, I offer empirical...

You're right that according to the JTB analysis of the concept of knowledge (it's really an analysis rather than an argument), propositional knowledge is identical to justified, true belief. Gettier cases, as you say, are meant to show that knowledge requires more than justified, true belief. But Gettier cases don't proceed by assuming a different analysis (or definition) of knowledge than the JTB analysis: if they did that, they would be guilty of begging the question against the JTB analysis. Instead, Gettier cases involve scenarios in which intuitively the subject lacks knowledge of a proposition despite having a justified, true belief of the proposition. We're supposed to agree that, intuitively, Smith doesn't know the proposition Jones owns a Ford or Brown is in Barcelona , even if we don't have in mind any specific definition of "knowledge." Compare: If I propose an analysis of the concept of a lie on which a lie is nothing more than a false utterance, you can refute my analysis by...

The reclusive behavior you describe will be familiar to many philosophers! The great Scottish philosopher David Hume (1711-1776) famously wrote that socializing with friends helped him escape from his philosophical brooding when he felt overwhelmed by it. But thank goodness for his philosophical brooding! Otherwise he'd have been a much less important contributor to human civilization. You've asked a psychological question, really, so I'm not equipped to answer it, but the list of philosophers who have preferred thinking over socializing is long and illustrious. I'd recommend that you look for psychological literature that discusses the personality traits of introversion and extroversion and their characteristics. If you should discover that extroverts typically "have less interest in learning things" or believe "they already know or understand all that they ever wondered about," then how sad for them. Keep inquiring!

I'd say yes . One way would be if (for whatever reason) you ceased to believe some proposition P that you formerly knew to be true. If belief is a precondition for knowledge, then you'd no longer know that P. Another way might be, while retaining your belief of P, to come to believe (or indeed even know) some proposition Q your belief of which undermines your justification for believing P and thereby deprives you of the knowledge of P that you formerly had. See Carl Ginet's article "Knowing Less By Knowing More" (linked here ).