The Laws of Logic
1. The Law of Identity
A=A or to put it another way, If any statement 'x' is true, then 'x' is true.
Example: An apple is an apple.
2. The Law of Non-Contradiction
A is not non-A.
Example: It cannot be both raining and not-raining at my home right
Or my cat cannot be a cat and not-cat at the same time.
3. The Law of Excluded Middle
Either A or not-A. Either statement 'x' is true, or it's opposite is true.
Example: Either it is raining outside as I type this, or it is not raining
outside as I type this.
(Right now it isn't)
4. The Law of Rational Inference.
A=B & B=C, Therefore A=C
Example: All men are mortal
Socrates is a man
Therefore Socrates is mortal
These laws of logic or thought were not invented by man. No, not even Aristotle. Aristotle gets the credit because of the old adage, Publish or Perish. These laws are universal, absolute, and invariant because these have their primary existence in the mind of God. In order to understand what you're reading at this moment you are utilizing these laws. In understanding the words you see you are using the law of identity. But in using that law you are also using both the law of excluded middle and noncontradiction for an understanding of the meaning of the words individually and in context. And in understanding the overall meaning of what I have written you are utilizing the law of rational inference.
While such musing may be fun, it doesn't really show how these laws are a reflection of God's character. For this we will need to look at some scripture verses. I'll break down the verse listings by each of the four laws.
The Law of Identity.
The law of identity comes from God's self-identity. The consequence of this law is that there is objective truth. Or to put it another way, this law refutes the notion that there is no such thing as absolute truth. Some verses that teach this law are:
Genesis 2:19 And out of the ground the LORD God formed every beast of the field, and every fowl of the air; and brought them unto Adam to see what he would call them: and whatsoeverAdam called every living creature, that was the name thereof. 20 And Adam gave names to all cattle, and to the fowl of the air, and to every beast of the field; but for Adam there was not found an help meet for him.
Exodus 3:14: And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you.
The Law of Noncontradiction.
The foundation for the law of noncontradiction is in the unchanging character of God. Because God never changes, we have assurance that what is true today shall also be true tomorrow. If water is made up of 2 hydrogen atoms and 1 oxygen atom today, this will be true in the future because God never changes. Without the assurance of God's unchanging character we have no foundation for believing that the future will be like the past. Here are two verses to show this law:
Malachi 3:16 For I am the LORD, I change not; therefore ye sons of Jacob are not consumed.
Hebrews 13:8 Jesus Christ the same yesterday, and today, and forever.
The Law of Excluded Middle.
The law of excluded middle is fundamental to understanding what has been called the Myth of Neutrality. There is no neutral ground in our lives. There are no shades of grey. An example of ignoring this law can be found in the ongoing debates about the so-called "separation of church and state." The claim of the antichrists is that if we have Christianity in government then it violates the establishment clause of our Constitution. But this is nonsense on two counts. First, our founding fathers regularly had Christian meetings and prayers in government. So removing Christianity from government cannot be the intended meaning of the First Amendment. But more importantly, in the vain attempt to have neutrality in government by removing Christianity, they have replaced it with the subjective religion of secularism. So we have an option. We can have Christianity, the foundation for all substantive culture. Or we can have subjective secularism which makes objective knowledge and ethics impossible. But what verses support this? Here they are two of them:
Matthew 12:30/Luke 11:23 He that is not with me is against me; and he that gathereth not with me scattereth abroad.
Matthew 5:37 (James 5:12) But let your communication be, Yea, Yea; Nay, Nay: for whatsoever is more than these cometh of evil.
The Law of Rational Inference.
The law of rational inference being founded on the previous three laws governs how we link ideas together to form new ideas. Scripture is to be the foundation for how we view reality (Metaphysics), how we know and what we can know (Epistemology), and for our ethics. Scripture doesn't contain information on how to start your car, but the belief that your car will start when you go out to start your car in the morning is governed by Scripture. How we interact with the world, and therefore our inferences about the world, must be governed by the general principles of scripture. Only the Christian worldview put forth in scripture gives us the ability to fulfill God's commandment found in Genesis 1:26. In order to fulfill God's commandment to establish dominion over creation we must do as the Puritans tried to do and learn to think God's thoughts after him. Though many modern scientists decry the Christian worldview, they borrow the very thing the denigrate in each of their experiments. Without God and the Bible, science would be impossible. A simple verse showing the basics of this law can be found here:
John 17:17 Sanctify them through thy truth: thy word is truth.
I find it helpful to remember the four laws this way:
Law of Identity: Naming
Law of Noncontradiction: Boundaries
Law of Excluded Middle: Rules
Law of Rational Inference: Thinking about names, boundaries, and rules.
This isn't original with me. You'll find it in many other online resources.