The Nature & Necessity of Logic

Craig S. Hawkins

Professor Craig S. Hawkins, President
P.O. Box 10375
Santa Ana, CA 92711-0375
(909) 861-6179

"`Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.'"
- Mark 12:30

The Nature and Necessity of Logic

Today (as in the past) many depreciate or outright deny the importance or the relevance of logic to a number of issues, but of particular interest to this paper, in the areas ethics, metaphysics, and/or religion. This is true of most (if not all?) postmodernists, most (if not all) Buddhists, Hindus, New Agers, neopagans and other occultists, of religious and non-religious individuals alike, and unfortunately of many Christians as well. Many people flippantly talk as if they could do without logic, "take or leave it," as if it was optional.

While the depreciations or denunciations of logic vary in the range of topics that are allegedly exempt from logic, or the intensity in which logic is down-played or simply denied, the above individuals have in common the concept of limiting the applicability, extent, or scope of the jurisdiction of logic/reason.(1)

Thus, there are various understandings of just what the limits of logic are, nonetheless, these individuals all attempt to limit the domain of logic. This is the key concept.

Are these views viable? Can one "take or leave logic"? Is logic only applicable to certain topics? Is logic optional or true only for certain realms of inquiry?

I contend that epistemologically or otherwise these perspectives are inherently flawed. Theologically, philosophically, and practically these perspectives are incorrect, indeed, they are self-refuting. In this paper I will expound on what I believe are some of the many problems inherent to these perspectives. I will attempt to demonstrate that these views are incorrect, worse yet self-stultifying, and that logic or reason is undeniably true, unavoidable, and applicable to all coherent discussions. That is, one cannot not use logic (at least not so and engage in an intelligible discussion at the same time). Logic is a necessary precondition of all intelligible thinking.

My objections to Buddhists, Hindus, New Agers, neopagans and other occultists, Christians, and all others who depreciate or out-right deny the necessity of logic for coherent conversations is that their views are not only false, but self-contradictory because their logic-defying views are based or contingent on logic. That is, for their statements to significance or meaning, or to even formulate them, the individual(s) had to utilize logic in the first place, thus refuting or contradicting the very view they are trying to establish or prove.

Due to space consideration I cannot discuss all the important aspects of logic or reason relative to our topic. I will have to limit my discussion to some critical considerations. Thus, for example, unfortunately, I will not be able to apply the laws of logic in detail to various arguments or claims being advocated today in ethical, metaphysical, and religious arenas.

Hence, while there are numerous problems with the above mentioned perspectives, I will have to limit my discussion in this paper to the following central concerns.


Before we proceed any further, we should define the term logic. "Logic is the study of the methods and principles used to distinguish good (correct) from bad (incorrect) reasoning.(2)" It is the study of the laws or principles of thought or reason, that is not just mere thought or thinking per se, but of the type of thought or thinking we term reasoning. Irving Copi states that "The distinction between correct and incorrect reasoning is the central problem with which logic deals."(3) Norman Geisler and Ronald Brooks tell us that "Logic is the study of right reason or valid inferences and the attending fallacies, formal and informal" (emphasis in original).(4)

The Undeniableness of Logic

Logic is undeniable, unavoidable, self-evident, or self-explanatory. One cannot not use it. One has to use it to refute it. All such claims against logic are self-contradictory self-defeating, self-refuting, or self-stultifying.

Thus, for all of people's rhetoric against logic, one cannot not use logic. It is impossible to think or engage in any type of coherent dialogue and not use logic. This is because, among other reasons, the laws or principles of logic are what are termed first principles--first principles of epistemology. Logic is indispensable for at least five reasons. (While there is some overlap among the following five points, they are nonetheless numerated in this manner to help make explicit the nuances and implications of logic.)

First, the primary principles or laws of logic are first principles of epistemology. There is no getting "behind" or "around them." They are axiomatic or self-evident. That is, we cannot not use them (see points 2 and 3 below). Peter Angeles states, among other things, that first principles are "Statements (laws, reasons, rules) that are self-evident and/or fundamental to the explanation of a system and upon which the system depends for consistency and coherence."(5)

Second, the very distinction between true or false or applicable or not only exists or has meaning if logic is true or applicable. Without logic (e.g., the law of non-contradiction) there would be no such things or concepts as true or false. Thus, there could be no true or false statements in the first place, such as logic is not true or it is false that it is applicable to a given topic. This is because the law of (non-)contradiction "...itself draws the line between true and false. So we can't call it false without assuming that it is true."(6) The same holds true with the other laws of logic. As Geisler and Brooks tell us:

Logic is built on four undeniable laws. There is no "getting behind" these laws to explain them. They are self-evident and self-explanatory. There is also no way around them. In order to reject any of these statements, one must assume the very principle he seeks to deny. But if you must assume that something is true to say that it is false, you haven't got a very good case, have you?
For example, the law of non-contradiction (A is not non-A) says that no two contradictory statements can both be true at the same time and in the same sense. Now, if someone tried to deny this and said, "The law of non-contradiction is false," he would have a problem. Without the law of noncontradiction, there is no such thing as true or false, because this law itself draws the line between true and false. So we can't call it false without assuming that it is true. The same thing happens when someone tries to deny the other laws: the law of identity (A is A), the law of excluded middle (either A or non-A), and the law of rational inference (emphasis in original).(7)

Third, furthermore, a statement's meaningfulness (let alone significance or truthfulness) depends upon logic. If logic is not true, or applicable to the topic at hand then the statement is meaningless. That is, a statement's very meaning or meaningfulness exists only because logic is true or applicable. Otherwise the statement could or would be both true and not true or applicable and not applicable at the same time and in the same sense, since it would no longer be true that statements cannot be both true and not true (false) in the same time and sense. Both are now true or applicable since a statement can be both true and not true (false) at the same time and in the same sense. Thus, one could just as well say that "logic is true or applicable to the topic at hand" in the same breath as the previous statement, or "I will see you Wednesday and I will not see you Wednesday," etc. Thus, to deny logic or state that logic is not true or applicable only has meaning if logic does apply to the original statement. But this refutes the original claim.

Thus, any statement or claim only has meaning, a fortiori significance or truthfulness, if and only if logic does apply or is true. Hence, the claim that "logic is not true or applicable" is meaningless unless logic is true, but in that case the original claim is false, indeed, self-defeating.

Fourth, to deny or try to disprove the need for, necessity of, or truth of logic one must first utilize it, thus disproving their original assertion. One has to use logic to try to disprove, refute, or even deny it. If one must use logic in the effort to refute it, then the argument is self-evidently not true. One has only proven its truthfulness or applicability (ironically in the very attempt to refute it).

To deny logic or say that it is false or not true or applicable to a certain topic entails the use of logic in the very assertion itself (thus, it is true or applicable). This is like a person who says, "I can not utter a word in English." But, they just did. They should either quit speaking English or retract the original statement. The original statement is false, indeed self-defeating. Further examples of these types of claims include:

  1. "Logic is not applicable to this topic."
  2. "This topic, view, or realm is `beyond' logic." The idea is that logic's reach simply does not extend to the topic.
  3. "This is just a case of the Eastern versus Western or Aristotelian bias or perspective on logic." The idea is that one is insisting on a Western worldview perspective, while ignoring or to the detriment of an Eastern or occultic view.
  4. "This is the mundane versus `spiritual' perspective."
  5. "This is merely the emotions versus the realm of rationality or logic."
  6. "This is the altered versus normal states of consciousness viewpoint."
  7. "This is a case of this plane versus other planes or levels of reality or existence."
  8. "This is only a case of this level versus other levels of meaning."
  9. "Logic is not true."

All these claims are based upon logic in the first place.

Thus, to deny logic or assert that logic is not true (i.e., false) or applicable is itself based upon logic. The statement or distinction itself is built or predicated upon logic. Logic had to be employed to formulate the assertion. The statement "logic does not apply" involves the distinction of "logic does not apply," versus "logic does apply." However, it is possible to make this distinction itself only because of the laws of logic. Therefore, logic is--must be--true or does apply. But, this is self-refuting or refutes the original claim.

Fifth, one cannot not use logic in the real world. Try driving to the grocery store while denying the validity of logic. (Indeed, what grocery store? The one that is and is not there?) One can not successfully cross the railroad tracks without it. Next time you're at a railroad crossing with an apparent train speeding down the line imagine thinking that the train is there and it is not there. Would you? No! Try this in the "real" world. (Why do Hindus and Christian Scientists look both ways before crossing the street?) Logic is necessary or indispensable in life. One literally can not live (long) without it!


All attempts to deny or refute logic fail. They are false (indeed, are meaningless or nonsensical), self-contradictory, or self-stultifying assertions.

Terms for a statement or proposition that does not fulfill or satisfy itself--its own criteria or requirements (of acceptability) include: self-defeating, self-refuting, self-stultifying, self-referential absurdity or self-referentially absurd. Examples of these type of statements include:

  1. A person saying "I do and do not believe in logic" or "logic is and is not true" (at the same time and in the same sense).
  2. "My brother is an only child."
  3. "All the statements I make are false."
  4. A person "saying I am and am not an atheist."
  5. A person who claims that they "do and do not hold to postmodernism" or "do and do not believe that postmodernism is true."
  6. A person who is and is not a New Ager or is and is not a neopagan.
  7. A person saying "I am and am not a Christian."
  8. A person saying "Jesus is and is not God" (the second person of the Trinity).

Logic is the straitjacket of life for those who argue insanely or, at least mentally, refuse to live in the real world! One cannot even cross the street, let alone the metaphysical highway without using logic. Logic is indispensable--period.

The Four Primary Laws of Logic

Many talk as if they could do without logic. However, many people do not even know what logic is, or what are termed by some, the four primary laws or principles of logic or thought. Many people only know the five letter word logic, but again, not what it really means or the laws or principles behind it. Thus, we should at least briefly explain the four primary principles or laws of logic.

One of the primary principles of logic is the law of (non-) contradiction. Basically it states that no statement (proposition, assertion, etc.) can be both true and not true--false--(e.g., A can not be non-A) at the same time and in the same sense. For example, it can not both be true and not true (in the same time and sense) that a person is and is not a Christian. All such statements are false. It is a first principle (it is axiomatic or self-evident) of thought or epistemology. (Thus, one cannot not use it. To deny it is like saying "I cannot utter a word in English.") The distinction between true and false is based on this principle.

The second primary law of logic is the principle of excluded middle. The law of (non-)contradiction simply states that A cannot equal or be non-A (or p & non-p). But both could be "quip," that is, neither true or false--simply not both--but not necessarily true or false either. But excluded middle states A or non-A, that is, a proposition is either true or false--it must be one or the other (and not quip!). Thus, a proposition or statement must be true or false. (See, e.g., Matthew 12:30).

The third primary law of logic is called the law of identity. It states that A=A or that "if any statement is true, then it is true."(8) An example would be Christ is Christ and not non-Christ (e.g., the Christ of the Bible is not the "Christ" of the cults or the occult.

The fourth primary law of logic is the law of logical or rational inference. An example of this principle is: if A=B, and B=C, then A=C. It's importance can be seen relevant to all discursive or non-axiomatic knowledge or reasoning. For example, the word trinity is not found in the Bible, but the concept is found in the Bible (see, e.g., Deut. 6:4; Eph. 1:3; John 1:1; 20:28; Acts 5:3-4; and Mark 12:29-30).

These four primary laws of logic are vital--essential--to all coherent or intelligible discussions or arguments. As I hope is evident, one cannot--in any intelligent sense--not use them (e.g., even when trying to argue against the laws of logic).

God, the Bible, and Logic

The supreme example in the Bible of what to do or not to do (of course, other than things like claiming to be God) is Christ. Thus, (in the context of our discussion) if Jesus, God the Son, the second person of the Trinity, used logical argumentation to validate His claims or points, a fortiori, how much more so for us! Indeed, this is exactly what we see Jesus doing. For example, consider Matthew 12:24-30:

  1. Argument from analogy (vv. 25-26)
  2. The law of logical or rational inference (v. 26)
  3. Reductio ad absurdum (vv. 25-26)
  4. Argument from analogy (v. 27)
  5. The law of logical or rational inference (vv. 28, 29)
  6. Argument from analogy (v. 29)
  7. The law of contradiction (v. 30)
  8. The law of excluded middle (v. 30)

Throughout His ministry and teachings Jesus consistently used logic to present and advance His claims.

We find the same method--the use of logic--used by His apostles (see, e.g., Paul in Acts 17:2-3, 11, 17, 22-31; 18:4, 19; 19:8-9; 26:25; and 1 Tim, 6:20; or Apollos in Acts 18:27-28). Dialegomai is the Greek word used in the above passages. It means among other things to argue, dispute, or reason.

The Value of the God Given Mind

We are created in the imago Dei--the image of God. This includes, among other attributes, the ability to reason. This entails the value of evidence and reason. As Charles Hodge informs us:

If the contents of the Bible did not correspond with the truths which God has revealed in his external works and the constitution of our nature, it could not be received as coming from Him, for God cannot contradict himself. Nothing, therefore, can be more derogatory to the Bible than the assertion that its doctrines are contrary to reason. The assumption that reason and faith are incompatible; that we must become irrational in order to become believers is, however it may be intended, the language of infidelity; for faith in the irrational is of necessity itself irrational....We can believe only what we know, i.e., what we intelligently apprehend.(9)

Uses of Logic/Reason

There are a number of ways logic/reason can be used or not be used (as the case may be). I want to quickly consider three options found among Christians.

The first is what is termed a ministerial use of reason. This is the use of logic/reason as a servant or "handmaid" to the Bible and theology. Logic/reason is not put on par with or above the Bible, but stands in a subordinate role to God's revelation. This is the role of reason that I am advocating.

The second type is termed a magisterial use of reason. This is the placing of logic/reason on par with or actually above the Bible. Here logic/reason (that of the individual or a group) is allegedly the final judge, arbitrator, or authority of truth. This is not the role of reason that I am advocating. This is an incorrect use--abuse--of reason.

The third use of reason (or more correctly non-use I should say) is the anti-intellectual approach. This is the position of depreciating or out-right denying the role of reason/logic in apologetics and other concerns of Christianity. Unfortunately, this is the view that many Christians, intentionally or not, advocate.

The Three Cs of Logic for the Christian

I believe that the only truly biblical option for the Christian is the ministerial use of reason mentioned above. I believe that this is true for at least three reasons. That is, we cannot comprehend, let alone confirm, let alone conform our thoughts and lives to God's revelation without the use of Logic.

First, if a person can not comprehend or apprehend the content of the Gospel, then certainly they can not understand it, and a fortiori they can not believe in it!

Illogical or self-contradictory statements and beliefs are incomprehensible in the sense that they are nonsensical. Nonsensical assertion are not to be believed, whether religious or "secular." They are to be seen and rejected for what they are--nonsense.

It follows therefore that reason and logic are necessary for intelligible and reasonable propositions, which are a necessary precondition for the communication of truth to individuals. Truth must be logical so as to be able to be presented to a person's mind as intelligible thoughts, so that they might be embraced or rejected. As Charles Hodge so precisely stated it:

In the first place, reason is necessarily presupposed in every revelation. Revelation is the communication of truth to the mind. But the communication of truth supposes the capacity to receive it. Revelation cannot be made to brutes or idiots. Truths, to be received as objects of faith, must be intellectually apprehended...The first and indispensable office of reason, therefore, in matters of faith, is the cognition, or intelligent apprehension of the truths proposed for our reception.(10)

Second, logic is necessary for confirmation of the Gospel. That is, since God does not contradict Himself, or ask us to believe contradictions or that which is inherently self-contradictory (see e.g., 1 Tim. 6:20), revelations from Him will not contradict previously given revelations, or the sound reasoning processes necessary to even comprehend these revelations. Hodge informs us:

If the contents of the Bible did not correspond with the truths which God has revealed in his external works and the constitution of our nature, it could not be received as coming from Him, for God cannot contradict himself. Nothing, therefore, can be more derogatory to the Bible than the assertion that its doctrines are contrary to reason. The assumption that reason and faith are incompatible; that we must become irrational in order to become believers is, however it may be intended, the language of infidelity; for faith in the irrational is of necessity itself irrational....We can believe only what we know, i.e., what we intelligently apprehend.(11)

Thus, in one sense, reason is accorded the purgative to judge the trustworthiness of an alleged revelation. That is, before an alleged revelation from God should be accepted, we need to first discern that it is in fact from Him. Again, Hodge has written definitively on the topic:

It is impossible that He should require us to believe what contradicts any of the laws of belief which He has impressed upon our nature [i.e., the laws of thought or logic(12)]...Faith includes an affirmation of the mind that a thing is true. But it is a contradiction to say that the mind can affirm that to be true which it sees cannot possibility be true. This would be to affirm and deny, to believe and disbelieve, at the same time....The ultimate ground of faith and knowledge is confidence in God. We can neither believe or know anything unless we confide in those laws of belief which God implanted in our nature. If we can be required to believe what contradicts those laws, then the foundations are broken up. All distinction between right and wrong, would disappear...and we should become the victims of every adroit deceiver, or minister of Satan, who, by lying wonders, should call upon us to believe a lie.(13)

It should be evident that faith is inherently reasonable. Its very nature demands such.(14) Moreover, since faith in Christ is self-commitment to the truth, necessarily, its content or what is believed corresponds to reality, as well as is consistent or non-contradictory. Thus, it fulfills the requirements of the two primary truth tests (the correspondence and coherence theories of truth). Remember, we are told that we are saved because we believe the truth (see, e.g., John 18:37; 2 Th. 2:13), and that conversely those who will not believe the truth are lost (see e.g., 2 Th. 2:10-11).

Third, we are to conform our thoughts and lives to God's revelation. But we cannot do this without the use of logic. For example, we cannot say that "Christ is both God and not God" or that "we are and are not to sin."

Thus, logic is indispensable for the Christian.

God gave us a mind and He expects us to us it (Mark 12:29-31). It is not true that the mind is a terrible thing, "so waste it." I submit that if we are going to glorify God as Christians and in sharing the Gospel with others, we must not ignore or in an unscriptural manner down-play the importance of the mind in the preaching or defense of the Gospel. (This is in actuality a form of false humility or false spirituality, and should be denounced for what it is--unscriptural and dishonoring to God!)


In this relatively brief paper I believe that I have shown that it is impossible not to use logic. It is undeniable and hence unavoidable. The question is how well or poorly one will use it, not whether one will use logic.

For the Christian, I believe that the case is clear. For example, we are told in 1 Corinthians 10:31 "So whether you eat or drink [or think] or whatever you do, do it all for the glory of God." We are told in 2 Corinthians 10:3-5 "For though we live in the world, we do not wage war as the world does. The weapons we fight with are not the weapons of the world. On the contrary, they have divine power to demolish strongholds. We demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ." I believe that reasoning well is one of those "weapons."

Logic/reason is undeniable, unavoidable, and indeed invaluable! We need to know and become competent in correctly using logic. We must train ourselves, our children, and the church to properly use logic. Moreover, it is an invaluable tool for dismantling non-Christian views. I believe that Christians are challenged and commanded to be competent--by the grace of God--in the proper use of logic.

"`Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.'"
- Mark 12:30


1. The terms logic and reason are used interchangeably in this paper.

2. Irving M. Copi, Introduction to Logic, 7th ed. (New York: Macmillan, 1986), 3.

3. Ibid., 5.

4. Norman L. Geisler and Ronald M Brooks, Come Let Us Reason: An Introduction to Logical Thinking (Grand Rapids: Baker Book House, 1990), 12.

5. Peter A. Angeles, Dictionary of Philosophy (New York: Barnes and Noble, 1981), s.v. "first principles."

6. Geisler and Brooks, Come Let Us Reason, 16.

7. Ibid.

8. Copi, Introduction to Logic, 306.

9. Charles Hodge, Systematic Theology, 3 vols., reprint (Grand Rapids: Eerdmans, 1979), 1:83-84.

10. Hodge, Systematic Theology, 1:49.

11. Ibid., 3:83-84.

12. For an excellent discussion of the relationship of biblical truths and revelation to the laws of thought or logic, consult Norman Geisler's tape "The Relation of Logic and Christian Theology," (Dallas: Quest Tapes, n/d). Also consult R.C. Sproul, John Gerstner, and Arthur Lindsley, Classical Apologetics: A Rational Defense of the Christian Faith and a Critique of Presuppositional Apologetics (Grand Rapids: Zondervan, 1984), 72-82.

13. Hodge, Systematic Theology, 1:51-53.

14. For a treatment of beliefs that are transrational or translogical, but not irrational or illogical, see 3:75-84 of Hodge's Systematic Theology.