The Biblical Worldview (Part I-VII:4&7; April & July, 1991) (Available in the book: Always Ready PA600)
© Covenant Media Foundation, 800/553-3938
Apologetics (Part 1)
By Dr. Greg Bahnsen
An army cannot be expected to wage a successful battle if its soldiers are unfamiliar with the various weapons they have at their disposal for dealing with the enemy. Likewise a builder cannot construct or repair a house if he does not know what kinds of carpenter and plumbing tools are available to him and how to use them. In the same way, Christians who want to defend the faith should prepare for answering the criticisms of unbelievers by familiarizing themselves with the "tools" of reasoning and argumentation that can be enlisted in apologetics.
Being Rational, Broadly Speaking
"God has not been so sparing to men to make them barely two-legged creatures, and left it to Aristotle to make them rational." So wrote John Locke (1632-1704).
The quip refers to Aristotle's famous work on logic and syllogism, Organon ("The Instrument" or "tool" of knowledge), in which the ancient philosopher lays out rules of reasoning and distinguishes between correct and incorrect forms of argumentation. Locke was not sold on the epistemological benefit of the syllogistic form of reasoning (viz., major premise, minor premise, deduced conclusion) explored by Aristotle. Locke would have been far happier with Francis Bacon's Novum Organum ("New Instrument"), which was published in 1620 and explored the rules of inductive or scientific reasoning - which was later improved upon by John Stuart Mill's System of Logic (1843), whose own understanding of the tools of rationality in turn has been expanded and bettered by twentieth-century studies of logic, argument, and method.
Locke was, of course, the famous English socio-political philosopher who authored Two Treatises of Government, as well as a student of the human knowing process who became known as the father of "British empiricism." He was raised in a Puritan home and lived through the events which brought about the Westminster Assembly. He was a contemporary of Milton, Newton, and Boyle - and like these great men of letters, he openly professed Christian faith, having high regard for the Bible:
The Holy Scripture is to me, and always will be, the constant guide of my assent; and I will always hearken to it, as containing the infallible truth relating to things of highest concernment.... Where I want the evidence of things, there yet is ground enough for me to believe, because God has said it; and I will presently condemn and quit any opinion of mine, as soon as I am shown that it is contrary to any revelation of the Holy Scripture."
At age sixty-three, in the year 1695, Locke went to press with a treatise entitled The Reasonableness of Christianity as Delivered in the Scriptures.
It was five years earlier (1690) that Locke had published his best-known work on the theory of knowledge, An Essay Concerning Human Understanding. In it he lamented the fact that the word "reason" is often used as though it were opposed to "faith." He wrote that, in his opinion, faith should not be afforded to anything "but upon good reason," thus dispensing with any tension between them. Locke insisted that to believe things arbitrarily, apart from reason, was to insult our Maker. This being so, Christians were called upon to understand, refine and train their faculty of reasoning. With that we must certainly agree - even if we cannot completely follow Locke's epistemology or theological conclusions. We should surely master the difference between reliable and unreliable ways of reasoning if we would honor Christ and become effective in His service.
God wishes for us to be rational: to exercise and improve our reasoning ability in understanding, propounding and defending the truths of Scripture. And as Locke observed, this reasoning ability does not begin or end with the teaching of Aristotle. To be rational is a trait much broader than the use of syllogisms (although they certainly have their place). The kind of rationality or reasoning that we will employ in defending the Christian faith involves not only study of formal logic (patterns or abstract forms of inference), but also attention to informal fallacies in ordinary language, the use of inductive reasoning, the handling of empirical evidence in history, science, linguistics, etc., and especially reflection upon the demands of an adequate worldview in terms of which all such thinking makes sense.
Indeed, God has not been "sparing" in His provision of various tools which defenders of the faith can use to cross-examine opposing worldviews and rebut the argumentation of those who challenge the Scriptures. These tools are also beneficial in cogently formulating and advancing the Christian worldview, based on the teaching of the Bible. By exploring these tools of rationality (or the conspicuous ways in which they are violated) we can improve our ability to set forth an answer for the hope within us as believers, as well as get a grasp on the elementary errors in reasoning which are often committed by unbelievers.
One will often find that unbelievers, both educated and uneducated, take the offensive against Christianity before they have become familiar with what they are talking about. In the place of research and honest assessment of available evidence concerning some aspect of the Bible, many unbelievers have substituted personal conjecture about what "seems likely" to them.
For instance, since the Bible was supposed to be written so many hundreds of years ago, it just "seems likely" to many unbelievers that we cannot trust the text of the Bible which we have in our hands today. Surely scribes have altered and supplemented the original text so much that we cannot be sure what was actually written by Moses, Jeremiah, John or Paul (if these characters were in fact the authors in the first place); for all we know, what we read in our Bibles came from the pen of some monk in the "dark ages"! This kind of ignorant criticism seems intellectually sophisticated to some unbelievers. After all, in our natural human experience, messages which are passed from one speaker to another usually get garbled or distorted or augmented, don't they?
To unbelievers who reason this way (about this or many other subjects related to the Bible), we must not tire of pointing out that they are relying upon conjecture, not research. It may "seem likely" that the Biblical text would no longer be reliable or authentic after all these years, but that "likelihood" is an evaluation which rests upon prejudice. The first prejudice is the assumption that the Biblical text is no different from any other written document which we find in our natural human experience throughout history - which, of course, begs the fundamental question over which the believer and unbeliever are arguing! If the Bible is, as it claims, the inspired word of Almighty God, then the history of its textual transmission may very well be quite different than other human documents since God would have ordained that its text be preserved with greater integrity than that of ordinary books.
The second indication of prejudice is that the unbeliever does not offer any concrete evidence that (say) some medieval monk tampered with the text before us today. This kind of remark is simply and arbitrarily advanced as a hypothesis to be endorsed for its "likelihood," rather than its empirical credentials. If we want to play that way, of course, we could - with equal arbitrariness -- conjecture that the words which came down to us as Paul's were actually written, not years later, but years before the time of Paul! Arbitrariness is a fickle friend to the scholar. Cut loose from any demand for evidence, we could believe any number of conflicting things.
The third indication of prejudice in the criticism of the unbeliever is that he or she has not taken account of the actual evidence which is publicly available regarding the text of Scripture. If the critic had taken time to look into this subject, he or she would not have offered the outlandish evaluation that the Biblical text is unreliable. This came home to me with great force after taking an advanced course on Plato in graduate school, a course which took account of the textual criticism of the literary corpus of Plato's works. Our earliest extant manuscript of a work by Plato dates from right before 900 A.D. ("Oxford B," found in a Patmos monastery by E. B. Clarke), and we must remember that Plato is thought to have written roughly 350 years before Christ -- thus leaving us with a gap of over twelve centuries. By contrast, the earliest fragments of the New Testament date less than fifty years after the original writing; the bulk of our most important extant manuscripts dates from 200-300 years after original composition. The text of the New Testament is remarkably uniform and well established. The reliability of the Old Testament text has been demonstrated by the discovery of the Dead Sea scrolls.
The overall authenticity and accuracy of the Biblical text is well known to scholars. Frederick Kenyon concluded: "The Christian can take the whole Bible in his hand and say without fear or hesitation that he holds in it the true Word of God, handed down without essential loss from generation to generation, throughout the centuries." Such assessments from competent scholars could be multiplied easily -- which only goes to show the prejudice that operates in the thinking of unbelievers who offhand criticize the Bible for "very likely" having a dubious text.
When we defend our Christian faith, then, we must constantly be on the lookout for the way in which the reasoning of unbelievers rests upon prejudicial conjecture. It crops up repeatedly. I have even heard some people mouth the radical opinion that "we have no literary or historical basis for believing that Jesus of Nazareth actually ever lived"! Can you spot the obvious indications of prejudice here? Such a criticism simply takes it for granted that the Bible itself should not be taken in any way as a literary source of historical information -- contrary to the general practice of even unbelieving historians of the ancient world. Moreover, such criticism does not show familiarity with the secular allusions to Jesus in ancient literature -- such as the reference by the Roman historian Tacitus to "Christus" who suffered "the extreme penalty ... at the hands of one of our procurators, Pontius Pilate" (Annals 15.44), or the reference by the Jewish historian Josephus to James "the brother of Jesus, who is called Christ" (Antiquities 20:9), etc. Criticism like this usually ends up telling us more about the critic (e.g., his prejudices, what he has not been reading) than about the object of his criticism.
There was a time when critics of the Old Testament ridiculed it for mentioning a tribe of people, the Hittites, which were (as yet) unknown outside the Bible; such presumed flaws in the Biblical record were taken as rendering it worthless as a historical document -- until Hittite artifacts and monuments began to be uncovered around Carchemish by archaeologists, beginning in 1871. The Hittite civilization is today one of best known cultures of the ancient world!
Archaeology has over and over again proved to be the enemy of Biblical critics, unearthing their negative prejudices and confirming the accuracy of the Scriptures in historical particulars. H. M. Orlinsky wrote:
"More and more the older view that the biblical data were suspect and even likely to be false, unless corroborated by extra-biblical facts, is giving way to one which holds that, by and large, the biblical accounts are more likely to be true than false...."
Even as unsympathetic an umpire as Time magazine, in a lead article entitled "How True Is the Bible?," had to admit:
"After more than two centuries of facing the heaviest scientific guns that could be brought to bear, the Bible has survived -- and is perhaps the better for the siege. Even on the critics' own terms -- historical fact -- the Scriptures seem more acceptable now than they did when the rationalists began the attack."
The simple point which I want to make here is that apologists need to be prepared to expose the prejudicial conjectures of unbelievers when they appear. Many of the negative preconceptions held by those who criticize the Bible or Christianity prove to be arbitrary or embarrassing, when pressed; such pressure should be humbly but confidently applied. There are large numbers of those who reject the Scriptures on the basis of things, after all, about which they are really not familiar or well studied. We must point out how unreasonable it is to rest upon prejudice and conjecture in any area -- but especially respecting matters of eternal consequence. The more people come to know "the facts" about the Bible's text and historical reports, the less likely they will be to dismiss the book out of hand.
Unargued Philosophical Bias
Another tool which the apologist may use in arguing with those who are critical of the Biblical message is to expose the philosophical precommitments of the critic which have been taken for granted, rather than openly argued and supported. Here is yet another broad indicator of how unbelievers fall short of being rational in their approach.
Consider this. Even if enough external, corroborating evidence were available from textual criticism, archaeology and related sciences to authenticate all of the ordinary data (linguistic, cultural, chronological, etc.) which we find in the literature of Scripture, there would still remain important features -- indeed, the most important features -- of the Biblical narrative over which conscientious unbelievers would intellectually stumble. We not only read of Hittites, high-places, houses, military battles, migrations and marriages in the Bible, we also come across healings, floating axheads, fiery chariots, water turned to wine, virgin birth and resurrections. When unbelievers read of miraculous events in the Bible, their first inclination is to say that such things cannot happen, thus disbelieving the written report of them. "We all know that people cannot walk on water; so this story must be fabricated."
Each of us is familiar with this line of reasoning. We engage in it ourselves at the checkout counter at the supermarket when we see the fantastic tabloid headlines ("Woman Gives Birth to Her Own Father!"). The implicit argument is that such things are impossible, therefore they could not have occurred. Unbelievers dismiss in advance the possibility of miraculous events, and in light of that unspoken premise they cast a doubtful eye upon the Biblical narrative. "Jesus did not rise from the dead because we all know that the dead do not rise." Unbelievers easily assume that people who live in the enlightened, scientific, twentieth century cannot accept the superstitions, myths and fairytales of the Bible. After all, we use refrigerators and computers today!
To conduct their thinking in a fully rational manner, however, unbelievers who doubt the Biblical narrative of miracles ought to pause to recognize and scrutinize their controlling premise. "We know that miracles are impossible." We know that? Unbelievers feel that they know that such events cannot take place because, having a scientific outlook, they are convinced that all of nature operates in a predictable, law-like fashion. "Miracles would run counter to the regularities of our ordinary experience, would not be predictable," they protest -- to which the astute apologist ought to reply, "Isn't that just the point?" If miracles were not extraordinary, they would not be miracles.
The unbeliever's bias against extraordinary events needs to be challenged for its rational foundations. Does the unbeliever know that all of nature operates in a law-like fashion? that there can never be exceptions? That is a lot to know, involving as it does insight into the very nature of reality and the metaphysical limits of possibility. What justification does the unbeliever have for his or her views here? If instead the Christian worldview is true, miracles are not a philosophical problem in advance; an all-powerful Creator and Governor of the world could certainly do things which are out of the ordinary and contrary to the regularities of human experience -- like raising the dead. To reject the Bible because of its account of miracles is, thus, philosophically to beg the question.
The fault here is not that critics of Christianity have philosophical presuppositions which they bring to the evidence and use in their reasoning. This is inevitable, for anyone -- whether unbeliever or believer. The notion that we can be characterized by philosophical neutrality in scholarship and argumentation is naive and unrealistic; indeed, I would argue that it is impossible. The problem is not that unbelievers have their presuppositions, but rather that they frequently do not recognize those presuppositions for what they are and offer no warrant or defense for them -- especially over against the conflicting presuppositions of others (like Christians).
Obviously believers and unbelievers approach the Biblical record of miracles with different controlling assumptions about what is possible, about God's existence and power, about God's intervention in the world, etc. It is part of the task of apologetics to disclose the character and function of these conflicting presuppositions in the argument between Christians and non-Christians. The debate must not, of course, end at that point, as though we are left with an irresolvable intellectual standoff between ultimate philosophical perspectives. The next step involves argumentation and comparison regarding the opposing presuppositions (or worldviews) of the believer and unbeliever, thus taking us closer to the heart of philosophical apologetics as discussed in previous studies. Only the Christian worldview makes sense out of the logic, science, morality, etc. to which both sides to the dispute appeal -- not to mention, alone makes sense out of the very process of reasoning and arguing at all.
 An Essay Concerning Human Understanding, Book IV, Chapter XVII (New York: Dover Publications, 1959 ), vol. 2, p. 391.
 Cited by the editor in the "Introduction" to John Locke, The Reasonableness of Christianity as Delivered in the Scriptures, ed. George W. Ewing (Chicago: Gateway Edition, Henry Regnery Co., 1964 ), p. xi.
 Locke later explained that the book was chiefly designed as a rebuttal to the Deists; they nevertheless applauded Locke's emphasis upon the place of reason in religion, thus leading secondary scholars too hastily to class Locke as a deist. The English Calvinist, John Edwards (not to be confused with the American, Jonathan Edwards), distorted Locke's intentions even worse, maligning him with the epithets of atheism and Socinianism.
 Readers should consult here various beneficial texts on Christian "evidences," but they should also pursue discussions of the varying use of observational data in theory-formation and argumentation: for instance, W. V. Quine and J. S. Ullian, The Web of Belief, 2nd ed. (New York: Random House, 1978); Stephen Toulmin, The Uses of Argument (Cambridge: University Press, 1969); Thomas S. Kuhn, The Structure of Scientific Revolutions, 2nd ed. (Chicago: University Press, 1970).
 See the works of Cornelius Van Til here (available through Presbyterian and Reformed Publishing Co.): for instance, The Intellectual Challenge of the Gospel (1953), The Defense of the Faith (1955), A Survey of Christian Epistemology (1969).
 Ancient Israel (Ithaca, New York: Cornell University Press, 1954), p. 6. Likewise, W. F. Albright has written that "archeological and inscriptional data have established the historicity of innumerable passages and statements of the Old Testament" ("Archeology Confronts Biblical Criticism," The American Scholar, vol. 7 [Spring, 1938], p. 181).
The Biblical Worldview (Part II-VII:7; July, 1991) (Available in the book: Always Ready PA600)
© Covenant Media Foundation, 800/553-3938
Tools of Apologetics
By Dr. Greg Bahnsen
An army cannot be expected to wage a successful battle if its soldiers are unfamiliar with various weapons they have at their disposal for dealing with the enemy. Likewise a builder cannot construct or repair a house if he does not know what kinds of carpenter and plumbing tools are available to him and how to use them. In the same way, Christians who want to defend the faith should prepare for answering the criticisms of unbelievers by familiarizing themselves with the "tools" of reasoning and argumentation that can be enlisted in apologetics.
Key Intellectual Sins
The first tool of apologetical reasoning which we have considered is that of pointing to the prejudicial conjecture into which unbelievers easily fall when they look for a way to dispute the truth of Christianity. A second tool to be used in apologetics is to expose the unargued philosophical bias which is usually packed into the criticisms generated by unbelievers.
In utilizing such devices as these, the apologist seeks to uncover the "presuppositions" of the unbeliever which determine (unwittingly or sometimes self-consciously) the conclusions which he will reach. We are constantly on the lookout for unargued, crucial assumptions.
At other times the apologist needs to challenge not simply the nature of the unbeliever's presuppositions, but the fact that those presuppositions are either arbitrary or inconsistent. Indeed, these are precisely the two key sins for any scholar: arbitrariness in his thinking or incoherence between different aspects of his thinking (and living). Defenders of the faith must never tire of pointing this out.
If people are allowed to believe just anything they wish to believe out of convenience, tradition or prejudice, they have abandoned the course of rationality, which calls for having a good reason for the things we believe and do. On the other hand, if people are allowed to assert (or rely upon) certain premises, only later to abandon or contradict those very same premises, then they have violated the fundamental requirements for sound reasoning. In both cases a person's thinking and beliefs become unpredictable and unreliable.
Presuppositions Which Do Not Comport with Each Other
When we talk to unbelievers about their views -- especially their worldviews -- we should be especially sensitive to hear or discern what their controlling assumptions are about the nature of reality (metaphysics), about the nature of knowledge (epistemology), and about what is right or wrong in human behavior (ethics).
Although not everyone thinks clearly and specifically about such matters in the abstract (according to underlying principles), and although not everyone will be able openly and explicitly to state what his operating assumptions are, nevertheless everybody utilizes some basic perspective regarding reality, knowledge and conduct. As we say, everybody "does" philosophy, but not everybody does it well -- not everybody reflects self-consciously about such matters and seeks a cogent and consistent outlook.
So Christians must learn to listen closely to what critics of the faith are saying and seek to identify what is being taken for granted by the critic. We must point out, then analyze and criticize, the presuppositions of our opponents. In the nature of the case, the conflict between the tenacious unbeliever and the faithful believer will come down to a matter of their differing presuppositions.
When we identify the presuppositions of the unbeliever, we will see in case after case (indeed, in every case ultimately) that the unbeliever has an unmanaged and irresolvable tension between his operating assumptions. His basic beliefs about reality, or about knowledge, or about ethics do not comport with each other -- do not work harmoniously with each other or outright contradict each other. Let's look at a series of simple illustrations.
(1) Tension within one's ethical perspective: Imagine that your neighbor expresses an outlook which can be summarized in the words of a well-known beer commercial: "You only go around once in life, so grab for all the gusto you can get!" That is, pleasure is the leading value in life, and there is no accountability for our conduct after this life. On the other hand, imagine that this same neighbor expresses indignation over a well-documented instance of police brutality, or over the oppression and invasion of a weaker nation by some tyrant, or over light sentences handed down to rapists, or over bribes accepted by government officials, or over racial hatred and discrimination, etc. (take your pick). These two views -- that pleasure is the highest value, but brutality (etc.) is to be condemned -- expose a conceptual tension within your neighbor's thinking. He is not being consistent. After all, if policemen or rapists or tyrants (etc.) get pleasure from what they are doing to others, then they should, on your neighbor's hypothesis ("go for all the gusto you can get"), pursue those very activities which your neighbor turns around and condemns.
(2) Tension within one's epistemological perspective: Imagine that you have a friend who is critical of your Christian faith, saying that you are superstitious and gullible. According to him, we should not believe anything that is not verified (or verifiable) by observation or more broadly by our sense perceptions: to put it simply, "seeing is believing." The problem with Christians, he thinks, is that they believe things simply on the alleged authority of God (speaking in the Bible). So you discuss this further with your friend. You ask how he came to hold the view that knowledge is limited to observation. He explains that he has been taking a course at the local college (or reading some book from the library), and the teacher (writer) convinced him that we can only trust our senses in determining what to believe in this world. You spot the tension immediately! Your friend criticizes Christians for believing things, not by observational verification, but on the authority of another (God) -- and yet he himself has come to believe what he does, not by observational verification, but on the authority of another (his teacher)!
Actually, the tension in his thinking is even worse. Regardless of how he came to his view that knowledge is limited to observation, that view itself is self-contradictory. Imagine some things which we know and can verify by the use of our senses. I know that there is a bird chirping outside my window. I know that fire is hot. I know that malaria is relieved by quinine. I know that my son mowed the lawn. And I know such things because I have perceived them (or could have perceived them) with my own senses. Now what about this? Your friend claims to know that knowledge is limited to observation. Did he have any sense perception of that alleged truth (as I do when I watch my son mow the lawn)? Of course he did not. He could not "observe" a conceptual limitation, much less a universal limitation. He did not "see" that all knowledge is limited to what we can see. Therefore, there is an irresolvable contradiction in your friend's thinking.
(3) Tension within one's metaphysical perspective: Imagine that your professor at school teaches a behavioristic view of man, claiming that all human behavior is determined by antecedent factors (particularly, stimulus-response conditioning) and is predictable, if we knew all those factors. Ultimately and in principle, the professor argues, human free will is an illusion. All of us think and do what we have been conditioned to think and do, given the variable factors of our environment. Imagine further that, when it comes time for you to take the final exam in his course, you cheat on the examination and are caught at it by the professor. He is indignant and insists upon imposing a strict penalty (say, flunking the course). If he does so, he exposes an open conflict within his views of human nature, does he not? By punishing you, he assumes that you were free to choose how to approach taking the test: you could study hard and prepare to answer the questions on your own, or you could more efficiently "ride" upon the effort put into the test by the student from whose paper you copied. If you could not help doing what you did -- given your previous conditioning and the variables of your environment -- it would be senseless to punish you for doing what you predictably did. Yet this is precisely what the professor had taught you in class about human nature in the first place.
(4) Tension between one's epistemology and one's metaphysic: Imagine that you have a colleague at work who graduated from college and fancies himself somewhat intellectual about matters of religion. According to him, there is no God and no spiritual realm (or spiritual events, spiritual forces) whatsoever. This physical world is all there is to reality. Moreover, this colleague finds it intellectually impossible to accept the Christian outlook because it contains what he deems logical contradictions within itself (say, that God is one yet three, or that God is loving and all-powerful but there is evil in the world). According to him, we cannot know anything to be true which conflicts with the laws of logic. The veiled problem in the thinking of your colleague is that his view of reality (metaphysic) does not comport whatsoever with his view of knowledge (epistemology). He cannot simultaneously and consistently be committed to the laws of logic and the view that reality is solely physical in nature. And the reason is obvious: the "laws of logic" are not physical in nature. You cannot touch or taste a law of logic; nor could you identify one with a sophisticated instrument devised by a physicist. Laws of logic are not physical, and thus given your colleague's perspective, laws of logic are not real anyway.
Common Logical Fallacies
We have just mentioned the laws of logic (and how materialism would preclude them). Because the laws of logic are so important to argumentation and reasoning -- precisely what apologetics is all about, as we said before -- we should pause to familiarize ourselves with some of the most common of those guidelines for reasoning. An effective defense of the faith will call for skillful use of logic in meeting the challenges of unbelievers and refuting their arguments, as well as in doing an internal critique of the unbeliever's own basic outlook.
Logic is the study of correct (reliable) and incorrect (unreliable) lines of reasoning or argumentation. The logician is concerned to learn what (a) kinds of premises or (b) patterns of inference can be relied upon to lead to truth in one's conclusions. When we consider the kinds of premises which are utilized in an argument formulated in ordinary conversation (in "natural languages" like English, German, Chinese, etc.), we are said to be dealing with informal logic -- not because it is somehow casual, but because it does not concern itself with "formal" languages (systems of symbols, connectors, etc.). Formal logic, as the name would indicate, is concerned with forms of argumentation or patterns of reasoning (where the predicates or premises have been stripped of particular content and rendered abstract by assigning them a formal symbol or token, as one does in algebra).
Informal fallacies point out the unreliability of certain kinds of premises for insuring the truth of the conclusions inferred from them. Some of the most frequent informal fallacies in reasoning would be the following:
(1) Resting a conclusion upon an appeal to popular sentiment
(2) Resting a conclusion upon an appeal to emotion (pity, fear, etc.)
(3) Resting a conclusion upon an appeal against (or in favor of) the person, authority, circumstances or history of someone advancing a particular thesis
(4) Resting a conclusion upon an appeal to premises which prove (if anything) something else altogether
(5) Resting a conclusion upon an appeal to the absence (or ignorance) of premises proving the contrary
In each of the preceding kinds of fallacious reasoning (1-5), the truth of the premise (or premises) used in an argument is irrelevant to the truth of the proposed conclusion. Even granting the premise(s), the conclusion need not follow; consequently, such lines of thinking are unreliable. In other forms of fallacious reasoning (6-10), the truth of the conclusion does not reliably follow from the premise(s) because of ambiguous or confused thinking. Here are some common examples:
(6) Resting a conclusion upon appeal to a premise (or premises) where terms are not being used in the same sense, or where questions of grammar or emphasis render the sense (and thus truth) of the premise(s) uncertain
(7) Resting a conclusion upon appeal to a premise which is merely the restatement of the conclusion or takes the conclusion for granted
(8) Resting a conclusion upon appeal to a premise which is stated in an overly general fashion (which does not recognize important qualifications, or which is known to be true only in a limited number or atypical set of cases)
(9) Resting a conclusion upon appeal to a premise (or premises) in such a way as to confuse the attributes of "parts" of something with the attributes of the "whole"
(10) Resting a conclusion upon appeal to a premise (or premises) in such a way as to confuse the causal and temporal connections between events, confuse different kinds of "causation," or overlook the complexity of causes for something
Finally there are kinds of informal fallacies in reasoning (11-15) which betray either an unfairness of mind and method in the person proposing the argument in question or a distortion of the facts. Some examples of this are:
(11) Resting a conclusion upon someone's inability to offer a single, simple or clear answer to a complex question (raising more than one issue), a trick question (emotionally loaded), or a (mis)leading question (creating a false impression or diverting attention from the specific issue)
(12) Resting a conclusion upon a forced choice between two alternatives which are erroneously presented as the only options
(13) Resting a conclusion upon a line of reasoning which evidences the use of a double-standard or special pleading
(14) Resting a conclusion upon an erroneous comparison between two things (which do resemble each other, but in irrelevant or insignificant ways)
(15) Resting a conclusion upon the mistake of treating concrete attributes or series of particular events as though they were an entity in themselves (metaphorical hypostatization or abstraction)
In addition to the above fifteen kinds of informal fallacies in reasoning, Christians who wish to defend the faith effectively should be familiar with the common formal fallacies which are committed in reasoning, as well as the most effective or frequent positive lines of argumentation which are available. For instance:
(16) The fallacy of affirming the consequent is committed when someone asserts a conditional premise (If P, then Q), then affirms what is implied (Q), and concludes that this proves what implied it (P). Such a pattern of reasoning is not reliable, as we can see from examples: "If Milton wrote Hamlet, then Milton is a great author. But Milton is indeed a great author. Therefore he wrote Hamlet."
(17) The fallacy of denying the antecedent is committed when someone asserts a conditional premise (If P, then Q), then denies the premise from which the implication is drawn (P), and concludes that what was said to be implied (Q) must not be the case. Such a pattern of reasoning is just as unreliable as the one we just examined. Take an example: "If Castro shot Kennedy, then Castro is a scoundrel. But Castro did not shoot Kennedy. Therefore he is not a scoundrel."
(18) A very valuable form of argumentation, known as "disjunctive syllogism," progresses in the following way: you first establish the premise that (at least) one of two propositions is true: P or Q. You next prove that one of these propositions is not true (i.e., establish not-Q). From these two premises, one may validly infer that proposition P must be true. Example: "Samantha poisoned the tea, or her husband committed suicide. But Samantha did not poison the tea. Therefore her husband must have committed suicide."
(19) Another persuasive line of reasoning (when used cautiously) is known as arguing "a fortiori" -- arguing from the lesser case to the greater case. If someone properly understands the nature of the greatness which is said to be increased, reasoning from the lesser case to the greater case can be very insightful. "If God holds those who have never heard the gospel accountable, how much more will He judge with severity those who have heard the gospel and openly repudiate it."
(20) Perhaps the most powerful tool of rebuttal which apologists can use is the line of argument known as "reductio ad absurdum" -- the project of reducing your opponent's particular premise or overall position to absurdity. In using this kind of argument your aim is to show that the opponent's premise entails a conclusion which is known to be false. Since it does so, the premise in question must itself also be false. (This is a rule in formal logic known as "modus tollens": from "If P, then Q" and the addition of "not-Q," the conclusion "not-P" necessarily follows.) Here is an example: "If there are no universal moral principles (as the relativist maintains), then it is invalid for one culture to condemn the activities of another culture. But surely it is morally appropriate for us to condemn in Germany the Nazi atrocities against the Jews (or in India the forced incineration of a widow on her husband's funeral pyre, etc.). Therefore relativism is not true."
Behavior Which Betrays Professed Belief
Finally, in order to highlight a tool which is useful and necessary for Christian apologists, we should mention that it is not a mark of rationality for a person to assert one thing, but then live contrary to it. This can be considered a kind of moral hypocrisy, but it is equally a form of irrationality or inconsistency or tension within one's reasoning -- since one belief is at work when he linguistically asserts a position, but a conflicting belief is evident when he behaves in a way contrary to that position.
The life of the unbeliever is riddled with such inconsistency. He will presuppose human dignity and attend a funeral to honor a dead friend or relative, even though he previously argued that man is, in principle, no different from any other product of evolution like a horse or dog. The unbeliever will insist that man is nothing more than a complex of bio-chemical factors controlled by the laws of physics -- and then kiss his wife and children when he goes home, as though they share love with each other. He will argue that in sexual relations "anything goes" (there are no moral absolutes) -- but then indignantly condemn child molesters or morally repudiate necrophilia. He will suggest that the things which happen in the universe happen randomly -- by "chance" -- but then turn around and look for regularities, law-like explanations of events, and uniformity or predictability in the things studied by natural science. The non-Christian does not have a workable worldview, and he exposes its weakness at every turn in his life.
God has not been "sparing" in His provision to us of a variety of effective tools for answering the criticisms of unbelievers and rebutting the claims of their conflicting worldviews. In dealing with the unbeliever, the Christian should be alert to point out the critic's
(1) prejudicial conjectures,
(2) unargued philosophical bias,
(3) presuppositions which do not comport with each other,
(4) logical fallacies, and
(5) behavior which betrays his professed beliefs.
In doing this we perform one of the key tasks of apologetics: refuting challenges and offering an internal critique of the position from which those criticisms arise.
 The immateriality of laws (of logic, of morality, etc.) -- indeed the immateriality of concepts, of justice, of love, etc. -- pose no automatic philosophical problem for the Christian worldview. Laws of logic are a human reflection of the mind of God -- of God's thinking -- regarding the conceptual and/or evidential-proof relations between truths (or sets of truths). Logical laws are elaborations upon the fact that God does not contradict Himself (His word is not "yes" and "no", 2 Cor. 1:18) and that it is impossible for Him to lie (Heb. 6:18).