Bill Schultz Persuade



The Epistemological Necessities for Persuasion

by Bill Schultz


Jeff Lowder recently circulated a draft essay entitled “Is a Proof of the Non-Existence of a God Even Possible?” In discussing the premise of that essay, it became clear to both of us that Jeff’s piece was centered on the issue of whether any human, using accepted processes of logic,1 could construct a proof to his or her own satisfaction. I had misinterpreted the intent of that essay as implying some ability to convince another of the validity of the proof. I had also given Jeff an off-the-cuff critique wherein I failed to properly analyze and organize my own thoughts.

What I began by saying to Jeff is worth repeating. An understanding of both the weakness and strength of this comment is critical to a full comprehension of what Jeff and I both believe to be a key point. In arguing for the affirmative of Jeff’s proposition in at least some circumstances, I said:

1. The definition for “god” must be falsifiable.

2. There must be agreed epistemological maxims.

If those two conditions were met, then I agreed that a proof for the non-existence of the “god” in question was possible. If either of those conditions were lacking, I asserted, such a proof was not possible.

The error I made with the first point, above, is that the doctrine of falsifiability is just one of many possible epistemological maxims. It really deserves no special significance, over and above all other epistemological maxims that someone might use to ascertain the truth.

The error I made with the second point, above, is that Jeff never intended his essay to be about the ability of the author of a proof to persuade others of the validity of that proof. Jeff only intended to address the question of whether it was even possible for an objectively rational person to create such a proof. Since we both recognized the need for some statement on the issue of persuasion through a process of ascertainment of truth, I was invited to address that additional part of the overall problem of achieving some kind of unified philosophical position in any given group of people.


As defined in my Random House Unabridged dictionary, the term “epistemology” is defined as:

a branch of philosophy that investigates the origin, nature, methods, and limits of human knowledge.

Ayn Rand explained the meaning of epistemology by replacing that word with the question: “how do we know what we know?” Two key questions within that realm are how do we acquire knowledge and how do we test the acquired knowledge for error. The former question generally involves some balancing between sensory experiences and mental reasoning, while the latter question delves into the heart of determining the truth or falsity of any particular piece of acquired knowledge.


In the 20th-century, virtually all popular philosophies have included, to one degree or another, recognition of various fundamental limits on the ability of humans to acquire knowledge. Furthermore, there has been a strong trend towards various versions of empiricism, which asserts that all knowledge results from experience. With some broadening of the definition of “experience,” that position now seems arguably true to the point of near-universal acceptance. The argument from the rationalists “that the mind comes with pre-formed categories that determine the structure of our language and ways of thought” can now be understood to have resulted from either pre-natal or post-natal experiences, or else from genetic transmission of characteristics selected for by the experiences of our forebearers. Thus, there truly is no a priori knowledge. There is only knowledge transmitted through our genetic heritage (which is subject to the general principles of evolution) or knowledge transmitted through our senses, even during pre-natal periods.

Knowing these two sources of knowledge, it becomes easy to grasp how limited the knowledge of any given human will be. No matter how much knowledge one acquires during life, it is (at least presently) not possible to transmit that knowledge to another human without forcing that knowledge through the senses of the other in what is generally a very time-consuming process of education.


Since all knowledge not passed by our genes must go through our senses, and since we all understand how easy it is to fool our senses into false characterizations of the true sense experience, we must have some methodology for ascertaining what is true and what is false. All such methods involve the application of mental reasoning to our raw sense inputs. Down through the many years of human intellectual evolution, we have developed many principles and mental procedures for shortening the time and increasing the likelihood of correctly ascertaining what is true and what is false.


As is noted above, this article began from an assertion of mine that nobody could become convinced of the validity of a proof of the non-existence (or existence) of any “god” without a set of commonly held epistemological principles. The central support of virtually all theist beliefs is “faith.” Those who are not theists generally deny the validity of any belief supported by “faith” alone. Thus, the failure to agree on the validity or invalidity of “faith” as an epistemological principle results in discourse that is totally lacking in communicative qualities. The theist asserts “faith” in support of some particular assertion of fact. The non-theist, who does not accept the validity of “faith,” automatically rejects the assertion requiring “faith” as a prerequisite, and is not in any way persuaded by the argument advanced by the theist. Each lacks the ability to accept the arguments of the other.

You quite simply cannot persuade someone of the validity of the proof of any given proposition unless all of the epistemological principles necessary to that proof are held in common by each participant. If I intend to use Ockham’s Razor to exclude some assertion of my opponent, but my opponent (or my audience) fails to recognize the validity of Ockham’s Razor for such a use, then I will fail to convince when I reach the point in my exposition that calls for the employment of Ockham’s Razor. This statement may be generalized for all of the epistemological principles I might employ in the proof of any given proposition.

If you are working out the proof of a proposition on your own, and you possess all of the skill necessary to reach a conclusion without committing an error of reasoning, then at least you will be satisfied of the correctness of your result. But the moment you attempt to present your proof to some other person, you must deal with not only the reasoning abilities of that other person, but also the epistemological principles that person has accepted as being valid. If this other person holds some epistemological principle(s) to be valid that you do not (or vice versa), and there is a consequent invalidation of your proof in the eyes of the other person, you can argue until you are blue in the face, but you cannot persuade the other person to accept your proof without first persuading that other person to change their position with respect to any differing epistemological principle(s).

For the purpose of this article, I assume that everyone involved in the attempted persuasion possesses the required reasoning skills. Given that to be true, and given a fully supportable proof of some proposition, the only factors left that could conceivably prevent agreement would be the failure to agree in advance (or during the persuasion) as to the validity of the epistemological principles required to be employed in order to reach the proof. If those epistemological principles can also be brought into agreement, then persuasion should result. On the other hand, a failure to persuade as to these epistemological principles that are different will most likely result in each side proclaiming the correctness of their original position, regardless of the evidence and abilities of the participants.


There was an e-mail message circulated several months ago that requested an opinion from many of us as to the advisability of continuing to promote debates between theists and atheists. These debates have been generally unsatisfactory, as each side usually proclaims itself to be the winner after the debate is over.

Given the principles outlined in this article, we now can understand how both sides may rationally feel that they won any given debate. Each side entered the debate with its own epistemological principles firmly in tow, and employed those principles to their best use throughout. The result was foreordained, not only by the epistemological principles of the debaters themselves, but also by the epistemological principles of those that hear, read, or otherwise evaluate the debate. Those who are at all inclined towards one side or the other will look at the evidence of the other side and proclaim: “how silly!” There cannot be any agreement on the validity of the evidence because there never was any agreement on the validity of the underlying epistemological principles required to evaluate the evidence presented by each side.

So, my ultimate conclusion is this: nobody should engage in debate without being prepared to recognize and challenge any false epistemological principles employed by the other side. Of course, proper preparation for debate should ensure that your own side avoids making that same sort of error. A lot of debates between atheists and theists are quite shallow, in that neither side makes any effort to challenge these false epistemological principles. Non-theists should, in particular, recognize that debate with any theist requires at least some challenge be made to the principle of knowledge derived from “an act of faith” alone. The belief that “faith” is a valid methodology for the ascertainment of “truth” lies at the base of all otherwise unprovable beliefs, and such belifs are central to nearly all forms of theism. If the unfaithful can successfully challenge the faith of their opponents, then the possibility of truly winning a debate over “a Proof of the Non-Existence of a God” will finally exist.



1. There are many epistemological maxims that mankind has developed to aid in logical analysis designed to ascertain “the truth.” Here are some examples of the principles and mental procedures we have developed to shorten the time to ascertain, and increase the likelihood of correctly ascertaining, what is true and what is false:

argumentum ad [label] – (Lat., argument from [label], where [label] is the agreed term for some well-known fallacy.) It is an error in reasoning to use any fallacy (of argument or reasoning) in the process of ascertaining truth. Accordingly, when one is recognized, it is usually a source of embarrassment to the user of the fallacy.

“faith – The conviction of the truth of some doctrine which is the result of a voluntary act of will.” (From “The Oxford Dictionary of Philosophy,” by Simon Blackburn.) The essence of fideism is that knowledge of the divine through “ordinary means” is most likely impossible, and that instead we make a voluntary choice to believe in such knowledge. All theists rely on faith as the basis of their belief. Many will even acknowledge that there is no foundation for their theistic beliefs other than their willing act of faith in choosing to believe. Thus, their faith becomes a central point of division with anyone who denies the propriety of faith.

“logic – The general science of inference.” (From “The Oxford Dictionary of Philosophy,” by Simon Blackburn.) A large number of logical principles exist, each of which may be validly employed, given a certain set of prerequisites. The use (or misuse) of logic is the central theme of the reasoning process.

“Ockham’s razor – The celebrated principle of William of Ockham that … entities are not to be multiplied beyond necessity.” (From “The Oxford Dictionary of Philosophy,” by Simon Blackburn.) This principle allows the elimination of any theoretically possible entity that can be shown to be unnecessary to the observed result. In a debate between a theist and an atheist, the atheist frequently uses this principle to demand that the theist show that there is some necessary contribution from “god” or else concede that “god” is unnecessary to the observed universe.

“reductio ad absurdum (Lat., reduction to absurdity) The process of reasoning that derives a contradiction from some set of assumptions, and concludes that the set as a whole is untenable, so that at least one of” the assumptions must be discarded. (From “The Oxford Dictionary of Philosophy,” by Simon Blackburn.)

“verification (or verifiability) principle – The principle central to logical positivism, according to which the meaning of a statement is its method of verification. Sentences apparently expressing propositions that admit of no verification (such as those of metaphysics and theology) are in consequence meaningless, or at least fail to put forward theses with cognitive meaning, capable of truth or falsity.” (From “The Oxford Dictionary of Philosophy,” by Simon Blackburn.) A similar principle, going by the name “falsifiability,” is central to the work of Karl Popper.


The text of this essay is Copyright © 1997, by William A. Schultz. All Rights Reserved. Used by permission of the author.


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