The Burden of Proof  

In philosophical discussions the burden of proof or, Latin: onus probandi, is said to rest with the person making the claim.  It is invalid reasoning, an argument from ignorance or, Latin: argumentum ad ignorantium, to contend that because something cannot be proved false it is assumed to be true, or that because something cannot be proved true it is assumed to be false.   Shifting the burden of proof is a significant issue in debates relating to the existence of God.

The same standard applies in the legal fraternity where the burden of proof generally rests with the prosecution, who must prove the defendant guilty by providing sufficient evidence to achieve a positive verdict beyond reasonable doubt.   The obligation lies with the claim maker, as the Latin maxim attests: semper necessitas probandi incumbit ei qui agit, which translates as, “the necessity of proof always lies with the person who lays charges.”

In science, a hypothesis is proposed and this is subject to systematic observation, measurement and testing.    The results are used to ascertain the success or failure of the proposition, where further investigation may proceed to attempt to replicate the same result, or use the result to provide predictions that would entail from its’ truth.   In all cases the default position is that the proposition is unproved prior to its consideration.

Atheists tend to claim that the theist bears the burden of proof to justify the existence of God, whereas the theist tends to claim that both parties have an equal burden of proof.  The Oxford dictionary defines atheism as follows:

 Disbelief or lack of belief in the existence of God or gods.

This definition allows for the subtle, but important, distinction between positive and negative atheism.   Positive atheism is the belief that God does not exist, whereas negative atheism simply lacks belief in the existence of god or god.   Antony Flew, in The Presumption of Atheism[1], has argued that negative atheism does not bear a burden of proof as it is not making a knowledge claim.   Negative atheism is simply the lack belief in God, a subtle but important distinction from the knowledge claim that God does not exist.  Atheism can be wide or narrow – some may be positive atheists in respect to the Omni God of the major montheisms, but negative atheists in regards to other concepts of God.   A wide positive atheist would assert that no Gods exist, and a wide negative atheist that he lacks belief in all Gods.

William Lane Craig argues that atheists have an equal burden of proof because they are making an equal knowledge claim to the theist.   Despite the dictionary definitions of atheism which all include lack of belief, he claims that a negative atheist view is an attempt to redefine atheism.

“Such a re-definition trivializes the claim of the presumption of atheism, for on this definition atheism ceases to be a view, and even infants could count as atheists.”[2]

Craig is attempting to belittle the atheist position of lacking belief in God due to lack of evidence.  This is clearly misguided, but it underlies a key vulnerability in his claim that atheists should bear an equal burden of proof.  Negative atheism is clearly an opposing view to all forms of theism, and can be distinguished from any religious belief in God or gods.   It should not be deprecated as an insignificant belief as it would be opposed to the observance and privileging of religious beliefs, which it would view as unjustified.   To be aware of holding this view tends to result in opposing unwanted religious impositions one’s own life, and on the lives of others.   It is an inconvenient view as it seems to avoid bearing any burden of proof.    When Craig mentions that even infants can count as atheists he also betrays an appreciation that, in his view, the default position would indeed be a presumption of atheism.

It is useful to note that whilst Christian apologists assert that atheists bear an equal burden of proof, they also have a tendency to argue that it is impossible to disprove the existence of God.

“It is important to realize something about being an atheist that even most atheists fail to acknowledge and that is that atheism requires omniscience (complete knowledge of everything).… An atheist is making a positive assertion that there is no God. The only way that anyone could make such an assertion would be to presume that he knew everything about everything.” [3]

The existence of God is described as a universal negative.   A universal negative would be the type of negative argument that is impossible to prove due to our limited knowledge of the universe.    A proponent may argue that just because there is no evidence for P, does not mean that P does not exist.   Black swans were assumed not to exist because everyone knew all swans are white by nature; in fact the term black swans became a by word for impossibility.   They were then promptly discovered in Australia.

To attempt to prove a universal negative is extraordinary difficult. It can only be achieved if the proposition is logically impossible or false by definition. Bertrand Russell once remarked that he would be at a loss to prove that the Gods of ancient Greece did not exist:

If I were asked to prove that Zeus and Poseidon and Hera and the rest of the Olympians do not exist, I should be at a loss to find conclusive arguments.

If we consider leprechauns or Bigfoot, we could conceivably demonstrate that they do not exist on earth, but then we would have to expand our search to the entire universe. If it is possible that something exists, it seems that disproving it is either a task of Herculean proportions, or practically impossible.

Therefore, unless we can demonstrate that God is logically impossible, or incoherent as a concept, then it would appear to be very difficult to disprove him. Thus, from a theist’s point of view, the burden of proof cannot rest on atheism.

(Of course, many atheists, including myself, do think the concept of God as generally understood in the major religions, is logically impossible and incoherent. However, this would not be accepted by apologists, and the attributes seen as incoherent or impossible could easily be revised.)

If the theist demands the atheist shoulders a burden of proof, and he also asserts that it is impossible to disprove the existence of god, then he is effectively demanding that the atheist prove the unprovable.   It is clearly nonsensical for the burden of proof to be placed upon any proposition that is unprovable.  Therefore, if we cannot prove a universal negative, then atheism cannot be expected to bear a burden of proof on the existence of God.

So the apologist needs to make a choice.   Does he believe that it is possible to prove a universal negative, or will he grant the atheist no burden of proof?   The claim that you cannot prove a negative is a self defeater.  As Stephen Hales argues it is folk logic to make this unsustainable claim, and that in the sense that we can prove anything by deduction or induction, we can prove a negative.  Therefore, the positive atheist should not be complacent.   Since he believes there is no God, whether in the narrow or wide sense, he should bear a burden of proof proportional to his claim.

It should be unnecessary to point out that we do not have an obligation to disprove those things we lack belief in.  When a hypothesis fails, it is not necessarily disproven; it has failed to be proven.  The proven and verified hypotheses are the ones we move forward with.  There is no positive reason to act on a hypothesis whose only merit is that it cannot be disproved.

Absence of evidence is not evidence of absence.

This oft quoted aphorism makes the point that the absence of evidence for God does not indicate positive evidence that God does not exist.   This is of course assuming that the nature of the entity or hypothesis being tested would not have necessitated evidence.  William Lane Craig argues in The Cambridge Companion to Atheism, Theistic Critiques of Atheism, that it in order to demonstrate that the absence of evidence provides a strong argument for disbelief in God:

….it is incumbent on the atheist to prove that if God existed, He would provide more evidence of His existence than what we have.[4]  

In a stunning twist the perceived lack of evidence for God is used to reverse the burden of proof on to the atheist.  This is equivalent to demanding the defense counsel prove their client is innocent by demonstrating the real culprit would have left better clues.  William Lane Craig then goes on to claim that there are two reasons why this is an enormously heavy burden of proof for the atheist to bear:

On at least Christian theism the primary way in which we come to know God is not through evidence but through the inner work of His Holy Spirit, which is effectual in bringing persons into relation with God wholly apart from evidence.  (2)  On Christian theism God has provided the stupendous miracles of the creation of the universe from nothing and the resurrection of Jesus from the dead, for which events there is good scientific and historical evidence….

This annuls his own argument as he introduces evidence in points 1 and 2 to show that there is no absence of evidence after all.  The incoherency is exposed as Craig appears to think that, given the absence of evidence of God, the burden of proof is shifted to the atheist to prove that this should mean that God does not exist, at which time he will announce that we actually do have plenty of evidence of God!  He has invalidated the notion that a lack of evidence is not evidence of absence, by seeking to provide evidence.  This seems to imply that he actually believes that the lack of evidence is indeed a significant barrier to reasonably holding belief in God, and may actually constitute evidence of absence.  Furthermore, it does seem reasonable to propose that if God exists there might have been some evidence by now.

One wonders if a statute of limitations could be placed on the absence of evidence for the existence of God; after all, theists contend that this absence will not last forever.   Absence of evidence does not indicate God does not exist, but it does absolutely nothing to encourage belief in the proposition that he does exist, and merely implies that it is more rational to withhold belief until provision of said evidence.

In the absence of evidence there is nothing to be implied about that proposition.   Perhaps the aphorism can be reformulated:

In the absence of evidence, absence prevails

In the absence of sufficient evidence we, perforce, default back to the position which existed prior to the hypothesis.    In assuming that the hypothesis that God exists has failed, we revert to the position that we can neither affirm, nor deny Gods existence.   The default position is that we cannot prove the proposition that God exists, and equally, we cannot prove the proposition that God does not exist.  We might recognize equally; that we have no reason to believe in the existence of God, and that we may not be able to disprove Gods existence.   Evidently, the default position is completely neutral to the question, so neither the positive or negative position is proved.

When we consider this in practical terms, the default position is epistemologically equivalent to the negative atheist position of a lack of belief in God or God(s).   Otherwise, we would not only need to demonstrate that it is rational to hold beliefs without any reason or evidence, but also that we can do so in the absence of a proposition, which is clearly absurd.   Axiomatically, the neutral position is effectively the same as lacking of belief in the positive assertion that God exists.

A common objection to the argument that the burden of proof lies on the claim maker, is that evidence does not necessarily determine our beliefs.  If we can argue that we hold justified beliefs without evidence, then we should not require evidence as a justification to hold beliefs.  Let’s consider some examples:

I know that other minds exist

There plenty of evidence that other minds exist, as seen through the effects they cause.    There is an important distinction between evidence and irrefutable proof.  We do not require irrefutable proof to rationally hold beliefs, so long as they are supported by sufficient evidence.  We may not easily be able to demonstrate that other minds exist, but nevertheless we know that they do; the question is how do we know, and whether it is by evidence.   We have an intuitive understanding of the workings of other minds due to their apparent similarity with ours, as we observe the effects of the minds’ workings in the actions of the subjects concerned.    When we have a conversation with another person we can often identify a thinking process, or a line of thought, that enables us to not only confirm that a mind similar to ours is at work, but also to predict the sort of argument that may be soon to follow.   We can also point to the extensive medical evidence of how the brain works, and how the different regions of the brain can be seen to be influenced by various phenomena.

We can use the past to predict the future

How do we know that the laws of physics will work tomorrow?  We might argue that we know this without evidence.  However, our evidence is contained in the past, in a series of periods of time where the laws of physics have remained unchanged.  We have an observable pattern of evidence that the physical laws of nature, such as the law of gravity, can be seen to be operating in a consistent and typical manner.    In fact, it is distinctly noticeable that throughout history there have been no verified suspensions of the natural order.

A friend tells me his sister has got a job working in town

This might be advanced to suggest that we would not question this proposition, even though it is not accompanied by evidence.  We could substitute this phrase with any number of equally unsurprising assertions, such as, ‘my mother had her hair cut,’ that we would encounter regularly, and would have no need of questioning.  The evidence in favor of accepting this proposition is our level of trust in our friend, combined with the unexceptional nature of the claim.  If we distrusted our friend, we might not accept this proposition.  If we trust our friend, and it is implied that we do, since he is our friend, we would tend to count that trust in favor of relying on his testimony, and this would therefore constitute evidence in favor of its truth.  This knowledge is most likely incidental to us – it may have no bearing on our immediate happiness – therefore we would not have an obvious incentive to demand its justification.  It is also a fairly mundane claim, the sort that would be easily demonstrated by evidence, if required, and the sort that we would not need to proportion a great deal of evidence to accept.   It’s very ordinariness, and our common prior experience of these sort of claims, and the context in which they are normally be made, leads us to deduce that there is usually little incentive to mislead, and this would also count as evidence in favor of its acceptance.  In addition, if we are not accepting this knowledge on evidence, one has to provide an alternative reason why we are accepting it.

When there is no evidence of something, it is more reasonable to assume that it does not exist, rather than it does exist.  We see that in all other realms of human thought.  Lack of evidence is taken as strong reason to form the view that that proposition is unproved, or that the thing does not exist.  When we have insufficient evidence we operate on the assumption that the hypothesis is denied, until that evidence is provided.  There is no reason whatsoever to allow a special pleading for the existence of God.

The default position is neutral on the position of God’s existence.  The burden of proof is on the claim maker to justify his claim by evidence.   At the least, negative atheism does not bear a burden of proof – simple lack of belief in God can only be altered by provision of evidence to the contrary.   As per previous, it is unsustainable for the theist to hold that the belief that God does not exist is a universal negative, unprovable by definition, and that atheism should bear a burden of proof.   This indicates we should be wary of the suggestion that proving a negative is impossible.  Sufficient evidence is the standard by which we measure rational belief.

If you do not agree then I offer the following challenge:

Name one proposition involving the existence of a tangible entity that is unrelated to religious belief that you believe in without ANY EVIDENCE.

(When I offer the caveat tangible entity I wish to exclude concepts or abstract ideas, such as ‘love’ or ‘justice’ that I anticipate might be offered as solutions.)

I welcome your ideas and comments

[1] Flew, Antony (1984) [The Presumption of Atheism, 1976], God, Freedom and Immortality: A Critical Analysis (reprint ed.)

[2] Craig, William, L., 2007, Theistic Critiques Of Atheism, The Cambridge Companion to Atheism, pp.  69-85.  Ed.  M. Martin.   Cambridge Companions to Philosophy.  Cambridge University Press, 2007.

[3] McFarland, Alex, 2007, The 10 Most Common Objections to Christianity, US : Bethany House Publishers, pg 37-38.

[4] Craig, William, L., 2007, Theistic Critiques Of Atheism, The Cambridge Companion to Atheism, pp.  69-85.  Ed.  M. Martin.   Cambridge Companions to Philosophy.  Cambridge University Press, 2007.