The various forms of philosophical (p.) skepticism in the study of epistemology seek to question, deny, or limit the categories of what is possible to know. While it is useful to point out that we don’t have the data to confirm or deny some claims, many skeptics go so far that they would be forced to live a lifestyle that is inconsistent with their beliefs. I argue that questioning the “existence” of knowledge as a whole probably serves no purpose, since either answer will have no bearing on the everyday criteria for making decisions and taking action.
General p. skepticism questions the prospect of “knowledge.” There are several schools of thought that can be found on the family tree of p. skepticism. The extreme form is called epistemological nihilism, in which all “knowledge” is denied. There is also epistemological solipsism, a theory stating that “knowledge” about the external world is impossible, but “knowledge” about the agent’s mind is possible. ‘Global’ p. skeptics claim that they hold no “absolute knowledge,” while ‘local’ p. skeptics question specific types of knowledge. My target is the multifarious forms of global (g.) p. skepticism including nihilism and solipsism, and there are three main issues with these positions that I will touch upon.
First, this debate has been prolonged by a failure to give proper attention to semantics. The quotations around the word “knowledge” in my explanation are present because I have difficulty pinpointing exactly to what g.p. skeptics are referring when they use the term. It wouldn’t be just to completely fault the deceased thinkers who would have benefitted from access to modern advances in neuroscience. Nevertheless, “knowledge” remains ambiguous even without modern scientific perspectives.
It could be that “knowledge” really is “Justified True Belief.” Or it could be some abstract thing we achieve when we fully “understand” such and such. Perhaps it could be as simple as a subconscious observation that we sense in our environment. Ever walk into a room with, say, blue wallpaper, but hardly pay it any mind? How conscious does one have to be in order to know that the wallpaper is blue?
A g.p. skeptic might respond, “Exactly. The point is that we have no clear idea of what knowledge is.”
But they forget that human beings are the authors of language. We get to decide exactly to what “knowledge” refers. Any label without a referent is a floating abstraction. The question should not be, “What is knowledge?”, but rather, “How should ‘knowledge’ be defined?” The question should not be “Does knowledge exist?”, but rather, “Is ‘knowledge’ a useful term, given its definition?”
The second issue is that some skeptics must act inconsistently with their beliefs in order to interact with their environment. Nihilists believe that there can be no “knowledge” about the external world, and therefore, it cannot be verified. Yet, if they want to do anything, they must act upon information they receive through their senses. If they believe nothing they receive should be characterized as “knowledge,” then fine. The discussion becomes semantic. Otherwise, unless the nihilist sits quietly until death (or is deaf, dumb, blind, etc.), then the beliefs he/she holds will be violated.
As justification, I propose this thought experiment: Try to think of just one instance in which a normal, conscious human being can act physically without being aware of something in the physical realm.
Finally, there is an almost comical response to g.p. skeptics from a philosopher named G.E. Moore. He essentially says (not an actual quote), “Look. Here is my hand. I am perceiving a human hand right now. That is a fact that I ‘know.’ If you do not think I know it, then let’s say that I am acquiring sense-data. One sense-datum that I perceive is the surface of my hand.”
Although he employs an intriguing way of engaging g.p. skepticism, if we take the analysis one step further, we arrive at an important point. It is that perception of the so-called “external world” is the default state of human beings. There are all these lights and sounds and feels going on that we report on and verify through language. “Stuff” happens with such frequency that there is not really any reason to deny knowledge of the external world, especially on the basis that we could be wrong about individual bits of knowledge. (Proving something false logically necessitates the truth of the falsehood). The burden of proof is on the denier of clear and obvious evidence that literally surrounds us at all times.
To reiterate, challenging “knowledge” as a useful term is not a poor challenge, but questioning the concept while presupposing an ambiguous meaning is problematic. Going too far with g.p. skepticism will result in an inconsistent lifestyle. Acting in accordance with one’s sense-data regularly, while globally denying that very same data is an incoherent position. Therefore, the only option by default is to accept the external world as a given. Even settling for an agnostic position, abstaining from belief in the external world, may conflict somewhat with taking action. As I like to say, half-seriously, in all its Objectivist glory, “Reality doesn’t care about your nuanced opinion.”