Logic is the art of using reason properly in our investigation after truth, and the communication of it to others. Logic is an essential requirement of rational thinking, without it communication would be impossible. There are three basic laws in logic:
1) the law of non-contradiction (A is not non-A),
2) the law of identity (A is A), and
3) the law of excluded middle (either A or non-A).
There are objections to the use of logic when it comes to theological issues. It is felt that logic is an attack on the sovereignty of God because if God is sovereign then He is not under subjection to anything outside Himself. Some feel that applying logic to theology is subjecting God to logic or human reasoning. The issue is not that God is subject to our human understanding, but He is subject to His very nature as a rational Being. Logic is not something that is beyond God that He is subject to, but God is logic; logic flows from his very nature. So then, God is subject to His rational, logical nature; but not as something exterior to Himself. Human reasoning or human logic comes from God, unless it is false reasoning. We were created in His likeness; we received the rational thought process in our very nature from Him. The laws of logic were in use eternally in God and also given to us from the beginning of creation. Therefore the laws of logic, which man discovered and is subject to, are a manifestation of God’s own rational nature.
God’s attributes are encompassed in His logical and rational nature. Concerning God’s omnipotence, He cannot do all things. God can do anything that is not a contradiction or impossibility. If something contradicts His nature, such as lying, then it is impossible for Him to do it. If something is physically impossible to do, such as ceasing to be Himself, then He can’t do it. God cannot contradict His own rational and moral nature.
Some contend that if God can contradict or break the laws of nature in a supernatural intervention, then God can also break or contradict the laws of logic. But one must remember that the laws of nature (physics) are different from the laws of logic (rational thought). God can have exceptions (miracles) to the laws of nature for they are created and descriptive of the way things usually are in general. But the laws of logic cannot have exceptions, they on the other hand, are eternal and prescriptive of the way things are and will always be.
Logic is a prerequisite to proper thought in all areas of life. We use the laws of logic everyday and in all we do. In objecting to the use of the laws of logic, one would have to use the laws of logic in order to reject them. This article (Logic) falls under the second proposition in the apologetic argument for Christianity. The ‘law of non-contradiction” establishes the fact that ‘Opposites cannot both be true’. This fact is essential when showing that Christianity is true and all opposed are false. Thus, logic is necessary in defending truth and the Bible, which purports to tell the truth concerning eternal and temporal issues.
The ‘First Principles’ are a set of logical laws or rules that are the basis for knowledge concerning reality. They apply to the real world, whether eternal or temporal. Without them we could not know what is known. Through these principles truth concerning reality is known and falsity is also known. The correspondence between being (reality) and knowing (the mind) is connected through these principles in everything we think and do. To deny the first principles is to affirm them. To say that these principles are untrue or do not correspond to reality is to use the principle of non-contradiction by saying that the opposite of the statement that these ‘principles are untrue and do not correspond to reality’ is untrue, which says that these principles are true and do correspond to reality. These principles are undeniable and indestructible. All people in all places and at all times use these principles, whether they realize it or not, in all their thoughts and actions. False worldviews, when broken down into the simplest form, go against these laws or principles of logical thought. The correct worldview will be submitted to these laws and will correspond to reality.
The twelve basic principles are:
1) the principle of existence (B is existent),
2) the principle of identity (B is B),
3) the principle of non-contradiction (B is not non-B),
4) the principle of excluded middle (Either B or non-B),
5) the principle of causality (non-B cannot cause B),
6) the principle of contingency (contingent B cannot cause contingent B),
7) the positive principle of modality (only necessary B can cause contingent B),
8 the negative principle of modality (necessary B cannot cause a necessary B),
9) the principle of necessary causality (every contingent B is caused by a necessary B),
10) the principle of existential necessity (necessary B exists),
11) the principle of existential contingency (contingent B exists), and
12) the principle of analogy (necessary B is similar to contingent B it causes).
Through the use of these principles we can come to logical conclusions concerning ourselves and concerning the Theistic God. When putting these principles into practice we know that one necessary, eternal, un-caused, infinite, independent, logical, personal, and moral Being exists. This Being’s attributes fit the attributes of the theistic God. For we are similar to the theistic God, but not exactly the same and we also are not completely different. We are similar to the theistic God in the fact that we are personal, rational, and moral beings. We are different in the fact that we are contingent, temporary, created, finite, and dependent beings.
The basic first principles regulate all proper thinking concerning reality. Our thoughts about God and our communication of these thoughts to others rely on the laws of logic. Even in the denial of these principles is the affirmation of them. This article (First Principles) falls under the second proposition in the apologetic argument for Christianity. If these principles are not correct, then we cannot know that ‘Opposites cannot both be true’ and all communication and conclusions about reality are confused and senseless. The establishment of these principles is essential for guiding our thoughts and contradicting false thoughts, which is necessary in the defense of truth.