The Law of Non-Contradiction Requires Christian Theism

In the beginning was the Word (Logos) and the Word was with God and the Word was God (John 1:1).

Aristotle on the Law of Non-contradiction Utilized in Individual Motion

One cannot say of something that it is and that it is not in the same respect and at the same time (Aristotle).

Aristotle observes that men must act in a definite way. This clearly demonstrates that men think that things in reality are one way rather than another. The Law of Non-contradiction (LNC; A~~A) compels one action over another. This is the reason people do not aim to walk into holes in the ground or fall over balconies; this reveals that in one’s actions one cannot avoid the actuality of the LNC. Their actions illustrate that they have an a posteriori notion that they (A) are not the sidewalk (non-A) on the bottom of the balcony drop, so if they want to avoid a painful collision with the sidewalk at the bottom, they must avoid falling from a balcony. The truth of the LNC cannot be avoided in human experience. This demonstrates that the LNC is true and if one verbally disagrees with such, one must depend on the LNC in one’s disagreement which shows that the LNC is indubitable; it’s pragmatically necessary and rationally certain.

Action is the spot where our beliefs collide with the truth. If a skeptic attempts to be skeptical concerning the LNC, he still must depend on it to avoid getting hit by a car or tripping over a curb (pedestrian = A, and car = non-A). It is obvious that a skeptic must depend on and presuppose the LNC even in one’s effort to be skeptical regarding its ever-persisting necessity.

“Let this then suffice to show that the firmest belief is that opposite assertions are not true at the same time” (Aristotle: Metaphysics).”

The firmest principle is a belief in the LNC (not so with Christian Theism; the Triune God is the necessary foundation for the Christian approach) forasmuch as it bears with it the presupposition that the LNC is necessary; a presupposition that is presupposed and required for any venture into human experience.

The Law of Non-Contraction: A Logical and Practical Necessity

“For though we love both the truth and our friends, piety requires us to honor the truth first” (Aristotle).

Devoid of the LNC, men could not know anything. One could not demarcate anything within science, philosophy or theology; all distinctions between all particulars would be impossible to draw, and the incapacity of making distinctions would make rational argument impossible. Aristotle noted that the LNC is an obligatory principle of empirical observation, rational inquiry, analysis, and interpretation that men cannot do without.

Aristotle discusses the LNC in Metaphysics IV and in chapter 11 of Posterior Analytics I. No one in the ancient world rivaled Aristotle’s exposition of the LNC. He wrote: “It is impossible for the same thing to belong and not to belong at the same time to the same thing and in the same respect.”

(Metaphysics IV 3). Additionally: “It is impossible to hold (suppose) the same thing to be and not to be (Metaphysics IV 3).” Thus it is impossible to hold the same thing to be “A” and “non-A.” He later noted that the “opposite assertions cannot be true at the same time” (Metaphysics IV 6).

Aristotle says that the LNC is an all-inclusive axiom, a universal axiom to all human endeavors. In of itself it lacks tangible subject matter, but applies to everything. The LNC is a first principle and is the most unyielding principle. Aristotle states that the LNC “is necessary for anyone to know any of the things that are” (Metaphysics IV 3).
The LNC is a truth condition that makes human experience and thinking possible; the world must adhere to it. Since human experience and rational thinking presuppose the LNC, its reality and humanity’s unyielding dependence on its truth, it is a universal. Human experience is rational which accounts for these aspects of our experience and not the converse. Human experience conforms to the LNC forasmuch as it is presupposed by intelligibility.

Jesus the Logos Required for the Laws of Logic

In the beginning was the Logos, and the Logos was with God, and the Logos was God … The the Logos dwelt among us (John 1:1 & 14).

The eternal Logos is a necessary condition of human knowledge about anything.

Jesus’ ontology (His being and essence) is a substantial element of Christianity, for He is the great Logos (John 1:1), and logic is an attribute of His being and nature. Christians are a community that can account for reason; as reason comes from the nature of God. The true God is the God of reason. Reason cannot be held over His head in a type of Eurythro Dilemma, but is a reflection of His nature; additionally we must espouse it in submission to His revelation in the Bible. Christians should base their worldview on God’s word and His character. The Laws of Reason (Laws of Logic) have no material content. One cannot put the laws of reason (A = A; A~~A) in a bowl and pour milk over them. The abstract application of reason also has no material content.
The laws of logic are essential (they are immutable universals) and an a priori truth condition for any communication. Logic is the foundational instrument necessary for all utterance, debate, science, mathematics, and learning. Without using the laws of logic, one could not deny that logic is mandatory for communication. The a priori ontic condition for the laws of logic is God. An important consequence of this truth: Christianity is not just rational, but Christianity provides the essential environment required for reason and rational applications.

Without the transcendent, immutable, and universal in reach God, one cannot justify or account for the transcendent, immutable and universal rules of logic. God is the required truth condition for laws of reason.

Also known as the laws of truth (Frege), these laws are a priori truth conditions for knowledge, discourse, and argument. Logic is absolutely necessary for the intelligibility of life and God is absolutely necessary for logic. Thus, the Triune God is, and has to be. And He alone is God. No other named god supplies the obligatory truth conditions for the intelligibility of this world.
See my New eBook that argues: God is the necessary ground for knowledge God and Logic: Proof, Rationality, and Theism HERE Also in paperback.