Aristotle and The Law of Non-Contradiction
Aristotle recognized that the LNC (law of non-contradiction) is most certain and necessary. He defined this law: “It is impossible for the same thing to belong and not belong simultaneously to the same thing in the same respect.”
He acknowledges that it is the most absolute and rationally binding principle of thought and action. Aristotle declares that “it is impossible to be in error about it.” He defines a contradiction (antiphasis) as a pair of assertions one of which asserts what the other denies.
Aristotle and Christian Apologetics: The Classic Proof for the Existence of God
Aristotle proposed that proof for God’s existence could be established.
He argued:
• All things change for all things are in motion.
• Change is a transitioning from that which is potential to that which is actual.
• When potential is actualized, change and alteration has occurred.
• No potential has auto-actualization powers.
• There must be a source and wellspring of actuality, the actuality that moves all things from potentiality to actuality. Lacking such, nothing would be actualized.
• Some things are actualized; consequently there must be an unmoved ground of actuality
• This must be the Unmoved Mover inasmuch as an infinite regress is not possible.
Today, most non-Thomistic scholars believe that Aristotle’s (and Aquinas’) arguments fail. Nonetheless, there has been a potent resurgence of Thomistic apologetics in contemporary philosophy and apologetics.
Transcendental Argument: Motion Presupposes God
Aristotle offered arguments based on observation and human insight. A dissimilar form of theistic argumentation is a Transcendental Argument (TA). A TA contends that if motion, then God. The precondition for any motion is God. For a worldview to have the capacity to account for motion it must provide countless compulsory operational features of experience. One such feature would be the identity of objects in motion. For an object to be in motion the object is identified: A. So that A is in motion. A is A (law of identity: LI). Additionally A is not the unmoved B (LNC). Without God, motion cannot be accounted for and all observation as well as calculating of motion fails. Thus non-theism does not succeed in making motion intelligible.
There isn’t a non-theistic view of motion that can make sense of “A” in motion. An atheist scientist cannot account for his use of the immutable laws of logic (LNC & LI)* in his identification and reasoning about motion. The LNC is not mutable. The human mind and the material cosmos are mutable; they are in perpetual flux. Hence they lack the ontic ability to account for the immutable LNC. It is transcendent, universal, and abstract. The Christian Worldview (CWV) supplies the necessary a priori truth conditions for the immaterial, unchanging, and universal laws of logic. The laws of logic cannot be found on a shelf or in a microscope slide. You cannot purchase a set of laws of logic on sale at a medical store. They are not tangible and material and they never change. The transcendent, immutable, universal, and immaterial God of scripture provides the pre-essentials for the transcendent, immutable, universal, and immaterial laws of reason utilized in evaluating motion. This demonstrates that it is impossible for the atheistic scientist to be correct in declaring nothing exists except the material world in motion. Forasmuch as motion presupposes God.
I.
• Motion presupposes the LNC (the Law of Non-contradiction).
• The immutable God, who has universal reach, has the ontic capacity to ground the immutable universal LNC.
• If motion then the LNC.
• Motion.
• Hence the LNC.
• If the LNC then God.
• The LNC.
• Therefore God.
II.
• Motion presupposes the LNC.
• Atheism is grounded on a mutable non-universal foundation (the cosmos).
• The cosmos lacks the ontic capacity to ground the immutable universal LNC.
• If motion then the LNC.
• Motion.
• Hence, the LNC.
• If the LNC then atheism is false.
• The LNC.
• Therefore, atheism is false.
A TA proceeds by establishing the premise that God is the necessary truth condition for the identity of anything in motion. It accomplishes this by demonstrating that God provides the foundation and the essential pre-environment for identifying “A” as not “Non-A” (LNC). The negation of theism is impossible since atheism does not succeed in providing the truth conditions for motion and it is internally incoherent.
Theism Avoids Irrationality
The denial of God entails absurdity for it undercuts the foundation for the Law of Non-contradiction:
• p = theism.
• Not p = atheism.
• p or not p.
• Not p is absurd since it fails to supply the truth conditions for the LNC.
• This leaves p.
God lives and the contrary is not possible. The God of scripture is not a God that we would construct if we were left to our own understanding. Christianity declares a revelation from a source that transcends mankind: the Bible. Christians must proclaim that God is the Father, and the Son, and the Holy Spirit: one God, inimitable, and indivisible; unaccompanied in brilliant glory, clad in magnificence, might, and perfect sanctity. Men should revere Yahweh forasmuch as the triune God reveals so much of His nature that is awesome and fear-provoking; righteous and inflexible. Awe and gratitude must be expressed since God sent His dear Son, Jesus Christ, to die on the cross for the sins of His people and rise again on the third day. Turn from your ways and trust in Jesus Christ.
John 3:15-21 that whoever believes in Him should not perish but have eternal life. 16 For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.17 For God did not send His Son into the world to condemn the world, but that the world through Him might be saved. 18 “He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil.20 For everyone practicing evil hates the light and does not come to the light, lest his deeds should be exposed. 21 But he who does the truth comes to the light, that his deeds may be clearly seen, that they have been done in God.”
for more see my Unique eBook for all eReaders and Computers: ARISTOTLE, FREGE, THE LAWS OF LOGIC AND THEISM HERE
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* Distinctions I Maintain Between Logic and the Laws of Logic
I. Logic: “The study of argument [not a quarrel]; a piece of reasoning in which one or more statements are offered as support for some other statement” (S. Morris Engel: With Good Reason).
Logic is: (1) The Science of Argument. (2) A Hermeneutical Tool. (3) A Science of Commitment (John Frame: DKG, p. xi).
Logic is the study of the methods and principles used to distinguish correct from incorrect reasoning (Irving Copi: Introduction to Logic).
II. The Laws of Logic: Laws of thought and reason that are immaterial, aspatial, atemporal, universal, obligatory, necessary, immutable, and absolute. Some academics identify them as the laws of thought, the laws of truth, or the laws of reason. Various scholars strongly prefer to name them the laws of logic because they are independent of human minds and are ubiquitous throughout all experience. All rational thinking (and communication) presupposes and uses the laws of logic. The Law of Identity (LOI) is A=A. The most well-known law is the Law of Non-contradiction (LNC): A cannot be A and Non-A at the same time in the same way (A~~A). A man cannot be his own father.
The laws of logic “are basic principles of reasoning” (Frame: CVT).
The laws of logic reflect the nature and mind of the God of the Bible; thus, they have ontological grounding—that is, they are grounded in thevery nature of truth itself and cannot be reduced to human convention, opinion or psychology. Without these laws, knowledge and rational thinking are impossible. To deny the laws of logic, one must use these laws in one’s attempt to deny them. Those who deny the laws of logic are participating in a self-defeating endeavor. The Law of Non-contradiction (LNC), the Principle of Contradiction (or the Law of Contradiction) is perpetually necessary and in the words of Aristotle: “One cannot say of something that it is and that it is not in the same respect and at the same time.” The laws of logic are a feature related to the systematic, non-contradictory structure reflective of the way God has created and fashioned things based on his own ontology; a characteristic of the way God thinks. Various scholars assert that the Law of Excluded Middle may have real exceptions.
Allan Bloom stated that “The earliest-known explicit statement of the principle of contradiction, the premise of philosophy, and the foundation of rational discourse” is given in Plato’s Politeia. Therein is where the character Socrates states, “It’s plain that the same thing won’t be willing at the same time to do or suffer opposites with respect to the same part and in relation to the same thing” (additional material on the laws of logic are found in my eBook God and Logic HERE)
The law of contradiction [LNC] cannot be thought of as operating anywhere except against the background of the nature of God” (Van Til: IST).



Hey Mike,
What would you say if an atheist said that laws of logic were just the result of the big bang? Why is it necessary for atheists to believe that the big bang could only produce the material? Why can’t the big bang produce both the material and non material? And what is wrong with saying they don’t know what the cause of them are? How does that logically follow that they can’t know anything? They know the laws of logic exist because they use them. Why is it so necessary for them to know how they got there?
I guess to put it simply…. how does “I don’t know where the laws of logic came from” equate to “I can’t know anything”? (they still believe in them) After Christians don’t know where God came from. We know He has always been there, but we can’t explain that either.
The matter, motion, and energy within the BB and the cosmos could not produce the LL since the LL are immutable and universal; not so with the ever-in-flux cosmos. A thing cannot give what it does not possess.
Not only does one not need to know where the LL came from, one does not even need to know, in any formal manner, that the LL exist. But the Christian WV accounts for the LL and strict materialistic non-theism cannot.
“I can’t know anything” would take a blog post or more to offer a proper exposition. Perhaps I will write one in the near future.
Well if the big bang created the universe, and the universe includes laws of logic, then why can’t atheists just say the big bang is responsible for laws of logic? It created immutable and universal entities in addition to matter, motion, and energy.
The Laws of logic are immutable and universal; not the mutable cosmos. A thing cannot give what it does not possess.
The laws of logic presuppose and require God:
• The laws of logic are immutable, immaterial, atemporal, and apatial.
• The cosmos is mutable, material, temporal, and spatial.
• The cosmos is not sufficient to account for the laws of logic.
• God is immutable, immaterial, atemporal, and aspatial.
• God is sufficient to account for the laws of logic.
I’m not saying the cosmos created laws of logic, I’m saying the big bang created the cosmos and the laws of logic.
Chris: 1 Bang is a temporal particular. The LL are atemporal universals. the BB lacks the ontic capacity to underwrite the LL. u cant give what u dont have.
Then the atheist might ask why do laws of logic necessarily have to be atemporal? Is that because otherwise you could say that “before” the “big bang” the universe could have both existed and not existed at the same and in the same sense?
*same time and in the same sense.
Chris: Yes, thats one important reason. Selected aspects of these truths will be unpacked in my post on “nothing.” Should be posted by next week.
I would say that the LI and LNC are fundamental and necessary aspects of reality (upon which gods would be contingent).