The Three Fundamental Laws of Logic
There are three laws that we use to determine the truth or falsehood of something. These determinations are known as the laws of logic. Some might consider a fourth, the “Law of Logical or Rational Inference,” which basically states that you cannot dispute the first three laws without using said laws in your argument against them. Confused yet? Let me explain. The very basis of rationality is rooted in these three laws. Basically, in order to disprove them, you would have to use them as the base of your argument. This is what we call a “contradiction” and contradictions can’t exist, they are false. It is important that we as humans know how to identify contradictions so that we can weed them out in our search for the truth.
This article will serve to show you that the best way to identify a contradiction is by taking something (say, a statement) and testing it against the laws of logic. If the statement fails to meet the requirements of one or more of these laws, then we know it to be a contradiction and can reasonably consider that statement to be inherently false. That being said, just because a statement is not a contradiction doesn’t necessarily make it true. That is why, in this particular case, a statement must pass the third law as well as the first two in order to be known as truth. Let’s go over the laws.
1. The Law of Identity. This law states that something is itself. A does not equal B. This law establishes that the term being used coincides with the subject being described. Within the barriers of language itself, words have multiple meanings. This law does not apply to a statement that uses the same word to describe two different things or even different aspects of the same thing. (Example: It is summer.)
2. The Law of Non-Contradiction. This law explains that the object described in the first law cannot be both itself and not itself in the same sense. A cannot be non-A. (Example: It can’t be summer and not summer at the same time, in the same place, and in the same context.)
3. The Law of the Excluded Middle. This final law expresses that the statement must be either true or false, it cannot be both. There either is or there isn’t. Either it is summer or it isn’t. This is the final determination of logical truth; the statement has to match reality.
These laws are fundamental in our ability to think and reason logically. By comparing anything to them we can determine the truth of that thing. These laws cannot be broken by anyone or anything and therefore serve as one of (perhaps the only) constant truths that the universe knows.