The a priori two step

There are a handful of things we know by intuition that are not necessary truths. Most other things we know depend on us knowing these handful of things. They include, but are not limited to, morality, the external world, the past, other minds, and the uniformity of nature. But within these intuitions, there are actually two things to know about each of them.

Morality

1. We know that there is a real objective difference between right and wrong.
2. We know some particular behaviors are right and others are wrong.

The external world

1. We know that there is an external world.
2. We know that particular things we perceive are part of the external world.

The past

1. We know the past actually happened.
2. We know some particular memories we have correspond to what happened in the past.

Other minds

1. We know there are other minds.
2. We know there's a mind behind the behavior of particular people and sometimes animals.

The uniformity of nature

1. We know the future will resemble the past.
2. We know that particular things will happen in the future because we've observed them repeatedly in the past.

In each of these categories, we are less sure about the particulars of the second items of knowledge than we are the first. In fact, we make mistakes when it comes to the second items of knowledge all the time. However, in each case, the fact that we can often be wrong with regard to the second is never a sufficient reason to doubt the first.

The fact that people disagree on morality, and the fact that we sometiems change our moral point of view shows that we often have incorrect beliefs about right and wrong, but that is no reason to doubt that there is such a thing as right and wrong.

Most of the time when we dream, we think everything we are perceiving is real, but none of it is. When we are awake, we see illusions and mirages. Some people experience hallucinations, phantom limb syndrom, or they hear things. Even in the case of people with psychosis who experience more than the usual amount of faulty perceptions, that is never a reason to doubt the existence of the external world entirely.

I've lost count of how many times I've heard people say, "Memory is notoriously unreliable." While I think that view is overblown, it is true that our memories often fail us. It's not just that we are forgetful. It's that we remember things differently than they actually happened. If you've ever been in a relationship for a significant period of time, you've probably had an argument over how something happened because you each remember it differently. I'm sometimes surprised when I read what I wrote in my journal years ago to discover things happened a little differently than I remember. Our memories are very fallible. However, that is no reason to embrace Last Thursdaism or doubt that there even was a past.

People are notorious for anthropomorphizing--attributing human traits (e.g thought and emotion) onto inanimate things. We also attribute the wrong mental states to things that have minds. We misread each other and misunderstand each other, but it's even worse when we project human traits onto other animals. Some people err in the opposite extreme and think animals have no thought or emotion. Some even go so far as to think animals are not conscious at all. With some bugs and worms, it's hard to even know if they have any conscious experience. However, the fact that we make all of these mistakes when trying to understand the minds (or lack of minds) of others is no reason in the world to doubt that there are other minds.

Hasty generalization is a fallacy we've all been guilty of at one time or another. It's probably the main reason superstition exists. We make generalizations by extrapolating from too few instances. We've all done it. Also, we often under-generalize. We refuse to learn from past experience. We can be stubborn and think next time will be different. However, the fact that we often make mistakes when reasoning inductively is no reason at all for us to doubt the validity of inductive reasoning.

Our confidence in the first item of knowledge under each category is why we exert so much effort toward being right about the second.

We debate moral issues and engage in moral reasoning because we think there are correct and incorrect answers to moral questions.

We rub our eyes when we suspect we're seeing things or ask others, "Did you hear that?" when we think we might've heard a suspicious noise. We do this to weed the bad perceptions from the good perceptions because we think there's a real world out there, and we want to make sure we're seeing it as it really is.

We write things down, look for corroberating testimony or evidence, strain our brains to remember how things really happened, and we retrace our steps in an effort to clarify our memories. We argue with people who remember things differently because we know that something happened. It's just a matter of finding out what.

When we initially notice patterns, we test them to see if they continue to repeat, and if so, under what circumstances. We formulate laws that describe in a mathematical way how we should expect the world to operate from here on out. We test these laws by making observations, and we extrapolate from the test to the rest of the world. If water boils at the same temperature under the same pressure every time we run the test, then we assume that's just the way water is, and it should apply just as well to samples of water we haven't tried to boil. We do these experiements because we know that experience can tell us what we should expect the world to be like going forward.

Most of the things you know, or think you know, can be traced back to these handful of a priori truths or truths like them. Others I didn't go into include causation, the law of parsimony, the notion that ought implies can, the reality of time, an enduring self, intentional action, object permanence, and the reliability of our cognitive faculties in general. For most people, the knowledge of these things is so automatic that they never even think about them. The knowledge runs in the background. But if you thoughfully ask, "Why do you think that?" for almost any random thing you know about the world, and you keep asking, you will eventually trace the belief back to one or more of these items of a priori knowledge.

Usually, that's where the line of inquiry stops. These items of knowledge are part of the foundation of all knowledge. They aren't inferred from something prior. The information is just built into us. We're hard wired to believe these things. Since these items of knowledge come pre-loaded into the brain of every reasonably developed human mind, and they are not inferred from evidence or argument, we know them by intuition. Intuition is immediate knowledge upon reflection. We don't turn our gaze outward to see if these things are true; rather, we turn our gaze inward and simply see what is written on the mind.

There are some people who attempt to find something even more foundational than these items of knowledge. They'll try to come up with reasons for why we should believe them other than intuition. However, the reasons always turn out to be less obvious than the truths themselves. That casts doubt on whether those reasons are what actually justify the beliefs or lead to the beliefs. Even if any of these attempts at arguing for one of these truths is a sound argument, the argument is probably not why we actually believe those truths.

It is possible for each of these things to be false. After all, none of them are necessary truths. But just because something is possible doesn't mean it's reasonable to believe. In the case of these a priori truths, it is unreasonable to doubt them, especially the first item of knowledge under each category. But that doesn't stop some people.