Wednesday, May 25, 2022

How rational instincts make it possible to know things

I was just looking for an old post I made on Reddit, and I stumbled on this comment and thought it would make a good blog post even though I've posted similar things a gazillion times before. Usually when I talk about this subject, I use the phrase, "rational intuitions" or just "intuitions," but so many people object to that term that I decided to use a different term: "rational instincts." I mean basically the same thing.

Okay, I just had something to say about rational instincts. What I mean by instinct is a natural inclination to affirm a proposition that exists independently of inference, evidence, argument, observation, etc.

An example of what I'm talking about is the natural inclination we all have to believe that our sensory perceptions are giving us true information about a real external world that actually exists. This natural inclination exists in all people. Nobody ever had to tell you that there was an external world. From as young as you can remember, you automatically assumed that what you were seeing and touching and hearing corresponded to something real out there in the world.

If not for trusting in the general reliability of our rational instincts, we would have no justification for believing in an external world at all. It's possible we are all plugged into the matrix or brains in vats or something along those lines. It's possible we're all dreaming or hallucinating. If you take this thought to its logical conclusion, it's possible that you are the only person who exists. There is no evidence you could point to that would prove there's anything in existence outside of your mind because any evidence you pointed to (such as your sensory perceptions) would depend on the assumption that your senses are giving you true information about the world.

You can't prove that the external world exists, but we are all rational in believing in the external world merely on the basis of our rational instincts, i.e. our natural inclination to affirm that our senses are giving us true information. This is just one example. There are several things we all naturally believe but that can't be proved. These beliefs happen automatically in people. You don't have to reason your way into them. People who deny these things had to reason their way out of them.

People aren't born with the idea that the external world is an illusion. That's only a view people adopt later on in life after engaging in philosophical gymnastics. The default belief of all people is that the external world exists. As long as we're talking about a mentally healthy person, that's the belief that automatically arises, and that the person takes for granted until philosophy comes along and talks them out of it.

As I said, there are a handful of these rational instincts we have. Some of the things we know through rational instinct are necessary truths, and some are contingent truths. There are necessary truths, like the laws of logic and the basic rules of geometry and math, that we know merely by inward reflection. There are experiments that show even dogs understand the law of excluded middle. A dog doesn't have to be taught this. The knowledge arises automatically with brain development. In the case of necessary truths, we can know these things with absolute certainty because we can grasp, by natural instinct, the necessity of them. You can tell, just by closing your eyes and thinking about it, that if two straight lines intersect, the opposite angles will be equal, and it's impossible for things to be otherwise.

Any argument you use to undermine the general reliability of rational instinct will necessarily be a self-refuting argument. The reason is because any premise you use in an argument against rational instinct will ultimately depend on the reliability of rational instinct. If you succeed in proving, with your argument, that rational instincts are unreliable, you will have undermined the premises that lead to that conclusion. Consequently, you will have refuted your own argument against rational instincts. So any argument against rational instincts is self-refuting.

Let's say, for example, that you point to the observations of science, or past experience, or any observation about the world to undermine rational instinct. You then have to justify your knowledge of the past, and you can only do that by appealing to your memory. But how do you know your memory is reliable? After all, it's possible you popped into existence five minutes ago complete with memories of a past that never actually happened. Or how do you know you made any observations at all? You can only know that by trusting in your memories and in your sensory perceptions.

It is only through rational instinct that you have any rational justification for believing much of anything. I am not saying that rational instincts are infallible. In the case of necessary truths, I do think they can be infallible, but in the case of things like the past and the external world, they are not infallible. But they are nevertheless generally reliable. The fact that we sometimes see things that aren't there or that we remember things differently than they actually happened is no reason to doubt the general reliabilty of our sensory perceptions or our memories. If we couldn't affirm the general reliability of our rational instincts, then we couldn't know anything at all about the past or the external world. It would be impossible to even have a conversation since by the time you got to the end of a sentence, you couldn't know how your sentence began or what you were even talking about because you couldn't trust your memory.

Moral instincts are just a subset of natural rational instincts. All mentally healthy people perceive a difference between right and wrong, and this perception does not go away just because people deny what their moral instincts are telling them. If we are rational in believing in the past and in the external world on the basis of rational instincts, then we're just as rational in believing in morality for the same reason.

No comments: