Following the example of the legal system, it has been proposed that in settling differences between theists and atheists, the onus of proof should be on the theist. The proposal seems to be a sound one. At the same time, however, such a methodological approach should not be called a presumption.

If a theist is defined as someone who believes in God and an atheist as a person who does not, then the question arises whether the onus of proof to defend their views rests on the theist or the atheist. The other possibility is that the matter is treated as a mere enquiry in which proof does not arise. Much as one would like to think that that is the ideal solution, the question is far too emotional and far too important to be examined in such an offhand way. The necessity for deciding on whom the onus rests is underlined during debates when the opposing parties often try and score points by emphasizing the failure of their opponent to prove what has been alleged. For instance, one frequently hears theists gloating over the inability of atheists to prove that God does not exist.

Unbelievers frequently object against such accusations by claiming that it is not possible to prove a negative. But that is not true. In courts of law parties to a legal dispute are often required to prove that something did not happen or is not correct and do so with success. Examples are the plaintive in a civil suit who manages to prove that the defendant failed to honour the terms of the contract into which they entered or the prosecutor who demonstrates to the satisfaction of the Court that the alibi of the accused, namely his evidence that he was somewhere else during the commission of the crime, is false. The real reason why atheists cannot prove that God does not exist is one that has to do with the manner in which some theists define “God”. Their tendency to describe their deity in negative terms makes it difficult, if not impossible, to distinguish from it from no being at all. Can a “being” that is, for instance, said to be unlimited, infinite, immortal, invisible and incorporeal exist at all? Does the theist who ascribe these qualities to his god not define him out of existence? Why does he expect the atheist to prove the reverse? (See in this regard George H. Smith Atheism The Case Against God P. 51 – 54)

Of course, the atheist will not know whether the theist’s definition of God is nonsensical unless the latter opens the discussion or presents his case first. That is also what happens in a court case. The Courts have held that in terms of the legal maxim ” Ei incumbit probatio qui dicit, non qui negat” (the onus of proof lies on the person who alleges, not the person who denies) the party that bears the onus must lead his evidence first followed by his opponent. (They are also required to address the Court before judgement in the same sequence.) It is not only a matter of fairness, but it must be done so that the defendant or accused can know what the accusation against him is and whether there is a case to answer. It is as a result of the example of the Law that Antony Flew (a philosopher) proposed in an essay entitled The Presumption of Atheism that the theist carries the burden of proof. According to him, the said presumption is, in his words, “…closely analogous to the presumption of innocence in the English Law…” (The Presumption of Atheism and Other Essays on God, Freedom and Immortality P. 13).

Although I agree with the principle that the onus should be on the theist, who is after all the person who alleges, I think it is unfortunate that Flew decided to call it a “presumption”. While it is true that even in the South African Constitution it is laid down that accused persons are “…to be presumed innocent…” (section 35 (3)(h) of Act 108 of 1996), the word creates the impression that atheism is presumed to be true and is accordingly granted a special status. Two considerations contribute to this view. The first is that if (as Flew implies) the atheist is regarded as the accused in a criminal case, then the theist must be in the position of the prosecutor who has to prove his case beyond a reasonable doubt. It is because of this high standard of proof very difficult to secure a conviction in a criminal case. Although he does not say so specifically, one gets the impression from Flew’s essay that he is of the view that the theist should similarly be required to prove his case beyond a reasonable doubt. If so, that is something with which I cannot agree. More will be said about it later on. Secondly, the word “presumption” also creates the impression that the atheist has an impregnable position while the theist has been condemned before he has even opened his mouth. The Law lends support to this view. In both English and South African law, the word “presumption” has another meaning that is in conflict with the presumption of innocence in criminal cases. It often happened before 1994 in South Africa that Parliament passed laws containing “presumptions” in favour of the State. They were meant to assist the prosecutor in securing a conviction by making it unnecessary to prove, for instance, certain elements of a crime. A particularly draconian law of this nature was the Abuse of Dependence-producing Substance And Rehabilitation Centres Act no. 41 of 1971 which created in section 10 a number of presumptions. One stated that if an accused was found in possession of a prohibited substance such as dagga (marijuana) of which the weight was 115 grams or more, it was presumed that the accused was dealing in the said prohibited substance. According to another one of the provisions, one was presumed to be a dealer if one accompanied a vehicle on which drugs were found. The Act, incidentally, also mandated minimum sentences in section 2. For a conviction of possession, the Court was compelled to impose a sentence of between 2 and 10 years imprisonment for a first offender while for dealing the prescribed sentence was between 5 and 15 years imprisonment. An accused could, however, rebut the presumption (by presenting evidence) but he had to persuade the Court of his innocence on a balance of probabilities. This was in conflict with the principle that the accused bears no onus and that the Court must acquit him if his evidence is found to be reasonably possibly true. Many of these presumptions were subsequently found to be unconstitutional by the Constitutional Court and were struck down. Apart from that, most of them offended common sense and increased the risk of an erroneous conviction.

But to revert to Flew’s presumption of atheism; what are the objections that have been raised by his critics and how valid are they? One that Flew discusses in his essay is the claim that the religious experience that the theist has of God cannot be subjected to the proof that the atheist demands. The problem with this argument is that such an experience does not qualify as perception and is not reliable knowledge that can be independently verified by third parties. Other objections were raised shortly after the publication of Flew’s essay in the Canadian Journal of Philosophy in 1972. A Christian philosopher, Donald Evans, argued in the same publication that Flew’s presumption was anything but neutral. He also claimed that since the Christian god is a mysterious ultimate reality, any debate between believers and unbelievers would be futile given that there are, according to Evans, “…differences in criteria of intelligibility and rationality between theist and atheist”. In a certain sense that is true. Although many theists are generally rational, they also manage to fence their religious beliefs off from this rationality. They accordingly have two sets of criteria in evaluating claims – one irrational one for religion and another rational one for everything else. Perhaps theists ought to explain their approach in a debate with atheists because unbelievers find these double standards objectionable. But it is unlikely to happen, for in such an encounter the onus will be on the believer while Evans clearly tries to avoid such a confrontation.

Not only have believers objected to Flew’s presumption, but some have even argued that it is the atheist that has to bear the onus of proof for his failure to believe in God. One such person is Ralph McInerny. See his essay published on the Internet at It will be noted that McInerny only advances a single reason for his proposition. According to him, there is a “prima facie argument against atheism drawn from tradition, the common consent of mankind both in the past and in the present time”. This argument from tradition is known in the informal logic as the ad populum appeal and is regarded as a fallacious argument. There are two reasons why the argument is invalid in this particular case. Contrary to what McInerny claims, not all people believe in the Trinity or even a deity of some sort. Moreover, even in those cases where people profess to believe in “God”, they often use the term in highly idiosyncratic ways. Some theists tell us that “God” is love while Donald Evans (above) prefers to call his deity “ultimate reality”. Other examples are Einstein and Spinoza who used the word “God” as synonymous with nature and the philosophers Henri Bergson and Alfred North Whitehead for whom “God” and creativity was one and the same. The consensus that McInerny relies on is accordingly illusory. Secondly, it needs hardly be pointed out that the majority of people have often been wrong. They were wrong when they claimed that the earth is flat and similarly wide of the mark when they maintained that the sun revolves around the earth. Who is to say that they do not err in believing that “God” (whatever that may mean) exists?

Not all atheists agree with Flew and his presumption of atheism. The Canadian philosopher Kai Nielsen criticized the idea in his book Philosophy and Atheism. According to him the two sides to the dispute regarding the existence of God raise equally important grounds for belief or disbelief so that it would be improper for either side to rely on an onus or presumption (P132). This cannot be correct. The disbelief that atheists have can only be understood and need only be explained once the theists have put forward and defended their beliefs. That is why they must start the debate. I can also not agree with Nielsen when he says that it would be “wildly unrealistic and …unreasonable …to require that all one’s reasonable believing must have grounds and that the strength of your belief should be proportional to the evidence for the belief.” (P.139). It may be unrealistic, but it is surely essential (and reasonable) to require that beliefs be proportional to the evidence – particularly where the beliefs have far-reaching practical consequences. To hold otherwise would be to invite disaster. In a related vein, Nielsen argues that it is unrealistic to require theists to furnish reasons for the grounds for their beliefs when many other irrational beliefs remain unexamined (P.141). It is surely unjust of Nielsen to imply that Flew has never examined irrational beliefs. Years before, Flew did exactly that when he examined psychical phenomena in his book A New Approach to Psychical Research (1953). At any rate, it is difficult to see what this has to do with the question of whether believers should bear the onus. I also couldn’t help wondering about Nielsen’s own religious views when I read this. He refers to himself as a fellow atheist of Flew (P.140), but with friends like him, who needs enemies? Nielsen concludes his attack by contending that Flew had not shown that the concept of God is an illegitimate concept. Only when that has happened, he says, the believer should be required to demonstrate the reverse (P.142). Again, Nielsen puts the cart before the horse. Common sense dictates that the theist explains his personal concept of “God” first and attempt to persuade the atheist of the validity of his belief. Only then will the atheist be in a position to criticize the concept if he deems it illegitimate or irrational. Following this procedure means saddling the theist with an onus to prove his case.

Once it is accepted that the burden of proof is on the theist, the question arises what he needs to prove. That will, of course, depend on the particular religion and branch within it of which the theist is an adherent. If he is, for instance, a Roman Catholic, he will at first need to define his trinitarian god in terms that make sense so that it is at least possible for it to exist. Some of the attributes traditionally imputed to the Christian god are such that they render him nonsensical or impossible. Providing a coherent and sensible definition of the traditional “God” is almost an insurmountable hurdle to overcome. See in this regard the essays collected by Michael Martin and Ricki Monier in the book they edited called The Impossibility of God. The believer will also have to explain whether the god that he believes in is anthropomorphic, transcendental or immanent. The god described in the Bible is anthropomorphic. Human characteristics are ascribed to him throughout the various books in the Bible. See for instance Genesis 1:27, Daniel 7:9-10 and Revelations 1:12-16. In response to criticism that such a glorified superman inspires little awe and reverence, it has become more fashionable these days to claim that God is transcendental. Such a god is not subject to the limitations of the material universe since he exists outside it. But as WT Stace pointed out in his book A Critical History of Greek Philosophy, the problem with such a being, who lives in a different dimension, is that there can be no interaction between him and the material universe and he could accordingly not have created it. An immanent god, on the other hand, permanently pervades the universe and the believers of this type of deity are usually pantheists like Einstein. If the word “god” is, however, used as a synonym for nature, then the question arises why it is necessary to confuse people by employing an ambiguous, if a not incoherent, word like “god”.

Proofs for the existence of God can only follow after that. Philosophical proofs of this nature date back to antiquity but were codified, as it were, in the thirteenth century by the Catholic theologian and philosopher Thomas Aquinas in his Summa Theologica (Part 1 Ⅰ Q2 A3). His so-called 5 ways (quinque viae) of proving the existence of God take up only a few paragraphs in a work that consists of several volumes. The Catholic Church still accept these proofs and maintain that the existence of God can be demonstrated by rational argument. This is known as natural theology. The most important proofs of Aquinas are the cosmological and design arguments and the argument from contingency. Some of the other arguments for the existence of God that have since been devised are the ontological argument (traditionally attributed to St Anselm) and the moral argument. All these arguments (and their variants) have been demolished over the years. See for instance, J.L. Mackie The Miracle of Theism P 30 – 149 and Michael Martin Atheism A Philosophical Justification P 79 – 228. In more recent times it has become fashionable to claim that the existence of God has been proved by science. The alleged efficacy of prayer and faith healing, the so-called fine-tuning of the universe (also known as the Anthropic Cosmological Principle) and Intelligent Design are all examples of this phenomenon. These claims have also been effectively refuted. For an overview see Victor J Stenger’s books Has Science Found God? and God The Failed Hypothesis with the subtitle How Science Shows that God does not Exist.

If the theist does succeed in crossing these hurdles, he will have to persuade his opponent that the deity whose existence he has just proved is indeed the Trinity and not one of the myriads of other gods like Ahura-Mazda, Shiva or Allah. Once that has been achieved, our hypothetical Catholic will have to demonstrate the correctness of the dogmas of his own sect (such as, for instance, papal infallibility, transubstantiation and the assumption of Mary).

The number of things that have to be proved by the theist is formidable indeed. With the odds so stacked against him, it would be unfair to expect him to discharge his onus of proof beyond a reasonable doubt. It is for that reason that I think that the theist ought to be given a reasonable chance and, like a plaintiff in a civil claim, should merely be required to prove his case on a balance of probabilities.

Although I have spoken of proof, it is seldom that a dispute between the two sides is adjudicated in a Court of Law which is, par excellence, the forum where judgement is given on the basis of whether a party has discharged its onus. It is not, however, that courts never rule on the validity of religious beliefs. When Jehova’s Witnesses, for instance, refuse that their children receive a blood transfusion or refuse to undergo compulsory military service on religious grounds, they are prosecuted and the presiding officer has to decide whether their defence is a valid one. But more often than not, disputes between academics regarding the matters I have raised take place in obscure journals where there is no one to judge whose argument carries more weight. With the advent of the Internet and the popularity of Youtube, however, formal debates between theists and atheists have become more frequent. This medium has the advantage that third parties watch the debate and may well change their religious views if they find a particular orator persuasive.

Protestants have generally been reluctant to confront atheists in such debates. They follow the lead of the prominent theologian Karl Barth who declared that “Belief cannot argue with unbelief: it can only preach to it!” (Quoted by Antony Flew in his book God and Philosophy P. 9). There is, however, one fundamentalist Protestant philosopher who is not only willing to exchange views with atheists but often invite them to debate him. He is William Lane Craig, a professor of philosophy at Biola University (Biola is the acronym for “Bible Institute of Los Angeles”). Craig holds two doctorates; the one in theology deals with the resurrection and the other in philosophy with the so-called Kalam Cosmological argument. He is also a skilled debater. When he was in high school, he was awarded the first prize in oratory during a competition that was held in the state of Illinois.

Many of these debates between Craig and his irreligious opponents (which included such luminaries as Richard Dawkins, Sam Harris and Christopher Hitchens) were recorded and are available on Youtube. It seems in these videos, or at least on the face of it as if Craig accepts that the burden of proof is on him. Just as in a court case where the person who bears the onus has to start, Craig always opens the debate. Unfortunately, however, Craig does not use the opportunity to persuade the audience that his beliefs are correct. Instead, he manipulates the process by demanding that the debate takes place in Los Angeles before Biola students so that he has home advantage. He is also a past master at misusing quotes from the writings of his opponents during the course of the debate to cast doubt on their integrity. When Craig is given the right of reply after his adversary’s address, he makes much of the latter’s failure to dispute each and every point that he, Craig, raised during his opening statement. (The same principle also applies in a court case. Judges normally accept that a party has admitted the evidence tendered by the opposition if it is not attacked during cross-examination). It goes without saying that Craig has a thorough knowledge of informal logic and that he uses it to his advantage during the debate. Unless his opponents are also experts in philosophy they will come off second best in the encounter.

In my view, the format of these debates leaves much to be desired. The audience are frequently unable to follow the arguments due to the complexity thereof. Because of this, they rely more on form than substance in coming to a decision. Some of those who debated Craig were simply not good speakers and because they did not sound persuasive, the audience summarily decided, without reference to the merits of their arguments, that they had lost the debate. Ideally, these contests should be presided over by a neutral judge assisted by two assessors who are experts in the fields that are being debated. A decision of a majority of them should be a more accurate reflection of the true outcome of the debate and may go a long way towards resolving the dispute over the existence of God.

Christo Roberts

I am a retired Senior State Advocate and I live in Cape Town.