In assessing reality, there are four primary ways by which we may know what is true or real and what is not.
- Facts - First we have facts, either those things which are by definition true, or things that are self-evident. 2 + 2 equals 4 and all men are created equal. Facts define our reality and are not debatable.
- Belief - Next are assessments of reality that we are convinced are true by the evidence around us. Much of our knowledge is actually belief rather than fact. We believe a certain form of government is superior to another; we believe man's behavior is (or is not) causing climate change; we believe someone is guilty or innocent of a crime. These are not facts, although they can be supported by a great amount of evidence and therefore be hard to argue against or refute.
- Experience - Third, we have knowledge based on experience, that is, what we have seen, touched, smelled, tasted, heard, or otherwise interacted with subjectively. I am not hungry right now because I just ate breakfast; this is my reality based on my experience. While occasionally, experience can be misleading or deceiving, it is usually safe to assume that if someone has experienced something, it is true. Arguing against what someone knows based on their experience if you have not had that experience is especially foolish. I would never claim to surpass my wife in knowledge of childbirth because she has had that experience and I have not, and never will.
- Hope - Finally, there is hope, what we wish to be true whether or not there is evidence for it, and whether or not it is or will be true. We hope a certain team will win the big game, but this is never certain until the event is concluded (Superbowl XLII). It is hard to argue with hope.
An important point that follows from this is that one cannot know something is not true unless it contradicts a fact. To say that something doesn't exist, that another's belief is false, or that no one has had a certain experience is folly; at best you can express doubt that something is true, never absolute certainty.
While nearly all human knowledge of reality comes from these four points, there is a fifth - God. God is the hope of many. Some claim to have experienced Him. Many believe in Him. Various philosophers have even debated if God is a fact. I would go beyond this by saying that God is not merely a fact, He supersedes even definitions and self-evident truths. God is. There is no debate, there is no argument, all of reality is based on this simple premise that God is. Therefore, those who define their reality questioning or even denying this basic premise are deceived.