On p. 149 of Religion, Reason, and Revelation Gordon Clark challenges anyone to state his position (theory) without making use of the law of contradiction.  Indeed, the necessity of the other laws of logic, the law of identity and the law of excluded middle, are equally necessary for meaning and rational discourse.  Absent the laws of logic, the result is nonsense, and if uttered, it is gibberish. (See Gordon H. Clark. Religion, Reason, and Revelation, The Trinity Foundation, Unicoi, TN 37692)

John Robbins wrote in a Trinity Review:

“In the act of speaking God reveals his rationality: The laws of speech are the laws of logic.  The rules of grammar are derivative from the principles of logic.  For a word – any word, human or divine – to mean something (and every word of God means something, for God does not talk nonsense), that word must also not-mean something else.  When God says, “Let there be light,” light does not mean dark; or bees, or matter; let does not mean do not let, write, or rent; be does not mean buy, destroy, or eat.  … “[I]n the beginning,” does not mean AD 2000 or even one second after the beginning.  This is the logical law of contradiction: Not both A and not-A.  If sounds and written symbols do not obey this fundamental rule of logic, they are mere noises in the air or mere scribbling on the paper; they are not words; they are not speech.  God can and does speak because, as John tells us, God is Logic.” (Trinity Review, #309b, Nov-Dec 2012, p.4)

To repeat then, “… [T]he law of contradiction…requires that a given word must not only mean something, it must also not mean something. The term dog must mean dog, but also it must not mean mountain, and mountain must not mean metaphor. Each term must refer to something definite, and at the same time there must be some objects to which it does not refer.” (Clark, p. 149)

Suppose the word mountain meant dog, and Bible, and books, and library. Suppose it meant everything.  If it did, it would mean nothing. If the word mountain meant everything, one could write a book of any length by writing: mountain, mountain, mountain, mountain, mountain....  It could mean the dog flew up the mountain.  It could also mean that World War III will be a nuclear war. In short, it could mean whatever one might imagine. 

“The point should be clear:  One cannot write a book or speak a sentence that means anything without using the law of contradiction. Logic is an innate necessity, not an arbitrary convention that may be discarded at will.” (Clark, p.150)

For those who argue that the laws of logic are mere linguistic conventions, let them construct an argument that refutes each law.  As Clark, Robbins, and others have said:  To refute the laws of logic requires that one use them, thereby demonstrating their necessity for all meaningful, rational discourse.

“In all our conversation and writing the forms of logic are indispensable: without them discussion on every subject would cease.” (Gordon H. Clark. A Christian View of Men and Things, Trinity Foundation, Unicoi, TN, p. 308)

MP3 Course in Logic by Dr. John W. Robbins, Trinity Foundation, Unicoi, TN.
For anyone who has an interest in logic, learning its source, depth, importance, and indeed, its necessity for all meaningful discourse, Dr. Robbins’ MP3 lectures are available to the public as free downloads.  Click Here  to download the MP3 tapes.  Scroll down to Collection 11: Introduction to Logic.

About Dr. John W. Robbins:
John W. Robbins was President of the Trinity Foundation for many years and up until his death in 2008.  He left a legacy of knowledge, wisdom, and scholarship which may be found in Trinity Reviews, books, pamphlets, and many MP3 tapes of lectures, seminars, and sermons.  His clear thinking and writing on a variety of subjects within economics, philosophy, and theology is, without a doubt, one of the most valuable resources for Christians everywhere.  (Pagans and militant atheists, including every variety of skeptic and seeker-of-meaning will find the Biblical answer to their questions or concerns in his writings.)

MP3 Collection 11: Introduction to Logic, 18 lectures by Dr. John Robbins:

1. Introduction to Logic
2. Definition of Terms
3. Logic and Theology: The Westminster Confession
4. Informal Fallacies, Part 1
5. Informal Fallacies, Part 2
6. Logic and Theology: Christ's Use of Logic
7. Definitions
8. Formal Logic
9. Logic and Theology: Paul's Use of Logic
10. Categorical Forms
11. Immediate Inference, Validity, Euler Circles
12. Logic and Theology: Empirical Apologetics
13. Homework Review
14. The Syllogism
15. Logic and Theology: Why Science Is Always False
16. Homework Review
17. Conclusion
18. Logic and Theology: Vantillian Apologetics

Robbins’ logic course is a subject falling under Scripturalism, a term he coined to describe the philosophy and theology of Dr. Gordon H. Clark.  Robbins: "Scripturalism is the logically consistent application of Christian -- that is, Scriptural -- to all fields of thought."  Robbins summarizes Clark's philosophy of Scripturalism in this manner:
1. Epistemology: Propositional Revelation (The Bible tells me so.)
2. Soteriology: Faith Alone (Believe on the Lord Jesus Christ and you shall be saved.)
3. Metaphysics: Theism (In Him we live and move and have our being.)
4. Ethics: Divine Law (We ought to obey God rather than men.)
5. Politics: Constitutional Republic (Proclaim liberty throughout the land.)

Subsequent posts will set forth Dr. Robbins' discussion of each of the above.  For now, here is a summary he wrote in The Trinity Review, An Introduction to Gordon H. Clark, Part 2, Number 102, August 1993:

Next:  Robbins’ view on the necessity of logic for all meaningful human communication.