Question:

How do you know that Occam's razor works? How do you know that logic works at all?

Answer:

If the question was merely, "How do you know that your reasoning, at this moment, is sound?", you'd have a mildly interesting topic in Psychology. The short answer, is to remember that the world itself always makes sense, even if the people in it don't, and if the workings of the nonliving, non-whim driven aspects of reality seem to no longer make sense, you know you have a problem. If, on the other hand, you seem able to anticipate observations that you haven't made already, and your decisions seem to work out, one might suspect that there is a reason why.

But, how do we know that logic works AT ALL?

This is a variant on the old fallacy of absolute skepticism - the belief that we can't know anything. The reply to someone who says that, is to ask him if he knows that for sure. If the answer is yes, then he has admitted, in principle, that it is possible to know something - the truth of what he just said, serving as an example. The modification of our rebuttal, is a simple one.

P : "How do you know that logic works?"

Q : "Well, I don't know it, therefore I do know it."

P : "Huh? That doesn't make any sense!"

Q : "So, what's your point? How do you know that it doesn't make any sense?"

P : "Well, it's a contradiction."

Q : "So, now you do believe in logic?"

The answer to our question is to note that we can not, in principle, even ask it, and that to merely have a conversation presupposes the possibility of reason.


As for Occam's razor, consider the multitude of statements that may be made on a given topic or the myriad of things that might exist, instead of the one that actually does in a given place. It is a recognition that given this, if we start plucking assertions out of the thin air, the vast majority of the time, they will be wrong. Thus, absent evidence to the contrary, our placement of the burden of proof on the one alleging the existence of something or truth of a theory (that is, our assumption that he is wrong until the evidence shows otherwise) represents a pretty good guess, as long as we don't ignore contrary evidence when it does appear.

Again, there is the fact that that which is alleged to be in controversy, actually isn't. When you see a distant cityscape, do you assume that the city is actually there, or do you consider the possibility that it is all a mockup, put in place to fool you, equally likely? When you fall asleep, are you afraid that invisible pixies who have been hiding by your bedside will slash your throat? Someone who seriously, consistently rejected this principle of inductive logic would be embracing a full blown case of paranoia, and such a wide variety of other psychoses, that he would never have been able to cross the street and get to us, in order to ask us such a silly question.

In other words, merely by being here, the one who argues against the principle shows that he doesn't actually believe in what he is saying and is wasting our time with pointless games. We may ignore his words with a clear conscience, for his actions have done his speaking for him.

Shall we go onto a more serious topic, now?