Maverick Philosopher: Strictly Philosophical

Burden of Proof, Appeal to Ignorance, Safety Considerations, and God

Presumption and Burden of Proof

Firearms instructors sometimes say that every gun is loaded.  This is plainly false as it stands, but a wise saying nonetheless if interpreted to mean: every gun is to be presumed loaded until proven unloaded. Presumptions are procedural rules.  To presume every gun to be loaded is to adopt a procedural rule to treat every gun as if it is loaded regardless of how antecedently likely it is that it is loaded.  Suppose the likelihood is near zero: I examined the gun carefully an hour ago and I found it to be unloaded.  Nevertheless, the presumption that it is loaded remains in force.  I continue to behave as if it is loaded.  For example, I don't point the gun at anything unless I want to destroy it.

I conclude that to presume that proposition p is not to assert that p is true, nor to assert that p is probably true, nor to assume that p is true, but to decide to act as if p is true.  A presumption, then, is not a proposition, although it embeds one.  A presumption is something like a decision.  More precisely, a presumption is the accusative or content of an act of presuming, an accusative that is not itself a proposition, but embeds one.   The accusative might be: to proceed as if the accused is innocent.  This embeds the proposition *the accused is innocent.* 

A presumption is not like a belief in the following important respect.  To presume that a gun is loaded or that a man is innocent is not to believe that it is or that he is.  To believe that p is to believe that p is true.  But to presume that p is not to presume that p is true; it is to act as if p is true without either accepting or rejecting p.  To presume that Jones is innocent until proven guilty  is not to believe that he is innocent until proven guilty; it is to suspend judgment as to guilt or innocence until sufficient evidence is presented by the prosecution to warrant a verdict one way or the other.  When I presume that p, I take no stand as to the truth-value of p -- I neither accept nor reject p -- what I do is decide to act as if p is true.

Presumptions must be defeasible.  (I suspect that an indefeasible presumption is no presumption at all.) The presumption of being loaded is defeated in a particular case by carefully examining the gun and showing that it is unloaded.  So while a presumption is not a proposition, it embeds a proposition that can be shown to be false.  Defeasible presumption and burden-of-proof are correlative notions.  (They are like rights and duties in this respect but also in that both are normative notions.)  In a court of law, for example, if the accused enjoys a presumption of innocence, as he does in the Anglosphere, then the accuser bears a burden of proof, a burden which, if properly discharged, defeats the presumption. 

Appeal to Ignorance?

So if  person A claims to person B that a certain gun is unloaded, the burden of proof is on A to show that it is unloaded; person B does not bear the burden of proving that it is loaded.  It is not just that he bears a lesser burden; he bears no burden. Indeed it seems that B would be within his epistemic rights were he to claim that his ignorance of whether or not the gun is loaded is good evidence of its being loaded.  But this is an appeal to ignorance.  It has not been shown that the gun is unloaded; ergo, the gun is loaded.

It has not been shown that ~p; therefore p gives us the form of the ad ignorantiam 'fallacy.'  Construed as a deductive argument, it is clearly invalid.  Construed as an inductive argument, it will be in many cases weak.  For example, suppose the gun is straight from the manufacturer and right out of the box.  Then the probability of its being loaded is very low, and the argument: This gun out of the box has not been shown to be unloaded; ergo, this gun is loaded is very weak.

Nevertheless, safety considerations dictate a defeasible presumption in favor of every gun's being loaded, whether out of the box or not, a presumption that places the onus probandi on the one who maintains the opposite.  So one might  conclude that the appeal to ignorance in this case is reasonable even though the argument is deductively invalid and inductively weak.

The situation is similar to that in a court of law.  The defendant is presumed innocent until proven guilty, so the burden of proof rests on either the state in a criminal proceeding, or on the plaintiff or the plaintiff's attorney in a civil trial.  In a criminal case the probative bar is set very high: the accused has to be shown guilty beyond a reasonable doubt.  Here too there seems to be a legitimate appeal to ignorance: if it has not been shown that the defendant is guilty beyond a reasonable doubt, the conclusion to be drawn is that he is not guilty.

We will have to examine this more carefully in a separate post.

Safety Considerations

There are 'safety' considerations in both the gun example and the law example.  It is because we want to be on the safe side -- and not get shot -- that we presume every gun to be loaded. "Better that a hundred guns be unnecessarily examined than that one sentient being be accidentally shot."

And it is because we want to be on the safe side -- and not sentence an innocent person -- that we presume the accused to be innocent until proven guilty.  "Better that a hundred guilty people go free than that one innocent person be wrongly convicted."

But now what about God?  Don't safety considerations apply here as well? If God exists, then our ultimate happiness depends on getting into right relation with him.  So why can't one make a legitimate appeal to ignorance here?  Now of course from the fact that no one has proven that God does not exist, it does not follow that God exists.  That is an invalid deductive argument.  That would be a truly fallacious instance of ad ignorantiam.  But it is also invalid to infer than a gun is loaded because it hasn't been proven to be unloaded, or that a man is innocent because he hasn't been proven to be guilty.  It just doesn't follow in any of these cases.  And yet we reasonably consider the gun loaded and we reasonably find the accused to be innocent.  And so why can't we reasonably presume God to exist on the basis of the fact that he hasn't been shown not to exist?  If the burden of proof rests on the one who claims that gun is unloaded, why doesn't the burden of proof rest on the one who claims that God is nonexistent?  We don't want to get shot, but we also don't want to lose our ultimate beatitude -- if ultimate beatitude there be. 

You can't say that that the burden of proof rests on the theist because he is making a positive claim; for there are positive claims that need no proof.  And you can't say that the burden of proof rests on the theist because he is making an existential claim; for there are existential claims that need no proof. If you claim that extraterrestrial intelligent beings exist, then the burden is on you.  But if you claim that there are Saguaro cacti in Arizona, then the burden of proof is not on you but on the one who denies it. Nor can you say that the burden rests on the theist because he is controverting the widely-accepted viww that God does not exist; the consensus gentium is that God exists.

Earlier I argued that we shouldn't bring BOP considerations into the God discussion at all.  But if we do, why doesn't the BOP rest on the atheist?

Pigliucci's Confusion

Massimo Pigliucci thinks that if one understands who bears the burden of proof in a trial, then one ought to see right away that the burden of proof rests on the theist.  For, "the burden of proof is always on the party making a positive claim, not on the one making a negative one."  This strikes me as confused.  It is true that the party making a complaint or bringing a charge is making a positive claim, but this is not the reason why the BOP rests on the accuser.  It rests on the accuser because of the presumption of innocence that the accused enjoys.  The BOP rests on the accuser not because his claim is positive but because of the procedural rule enshrined in our system of law according to which one is presumed innocent until proven guilty.

It is not true that the BOP is always on the one who makes a positive claim.   'That hillside is studded with Saguaro cacti' said to my hiking companion needs no proof.  I shoulder no probative burden when I make a commonplace observation such as that. Therefore, the following is an unsound argument:

Everyone who make a positive claim bears a BOP.
The theist makes a positive claim.
ergo
The theist bears the BOP in his debate with the atheist.

I argued above that if BOP considerations are relevant to the God debate, then the BOP is on the atheist.  To appreciate the argument I gave, you have to realize that the God question is not merely theoretical.  It is a practical question.  In that respect it is like the gun safety and court room cases.  My interest in whether or not a particular firearm is loaded or unloaded is not merely theoretical, or I should say, not at all theoretical.  It is a practical interest in maintaining the health and physical integrity of myself and the people around me.  Similarly with the law.  If you are accused of homicide you are in deep trouble and face the loss of your liberty or your life.  Arguably, the God question is in the same boat.

So I invite you to accept one or the other of the following conclusions.  The BOP is borne by the atheist.  BOP considerations should be kept out of the theist-atheist debate altogether. 

Are Burden-of-Proof Considerations Relevant in Philosophy?

1. The question this post raises is whether it is at all useful to speak of burden of proof (BOP) in dialectical situations in which there are no agreed-upon rules of procedure that are constitutive of the 'game' played within the dialectical situation.  By a dialectical situation I mean a context in which orderly discussion occurs among two or more competent and sincere interlocutors who share the goal of arriving as best they can at the truth about some matter, or the goal of resolving some question in dispute.  My main concern is with dialectical situations that are broadly  philosophical.   I suspect that in philosophical debates the notion of burden of proof is out of place and not usefully deployed.  That is what I will now try to argue.

2. I will begin with the observation that the presumption of innocence (POI) in an Anglo-American court  of law is never up for grabs in that arena.  Thus the POI is not itself presumptively maintained and subject to defeat.  If Jones is accused of a crime, the presumption of his innocence can of course be defeated, but that the accused must be presumed innocent until proven guilty is itself never questioned and of course never defeated.  The POI is not itself a defeasible presumption.  And if Rescher is right that there are no indefeasible presumptions, then the POI is not even a presumption.  The POI is a rule of the 'game,' and constitutive of the 'game.'  The POI in a court room situation  is like a law of chess.  The laws of chess, as constitutive of chess, cannot themselves be contested within a game of chess.  In a particular game a dispute may arise as to whether or not a three-fold repetition of position has occurred.  But that a three-fold repetition of position results in a draw is not subject to dispute. The reason there is always a definite outcome in chess (win, lose, or draw) is precisely because of the non-negotiable chess-constitutive laws. These laws, of course, are not inscribed in the nature of things, but are conventional in nature.

As I pointed out earlier, defeasible presumption (DP) and burden of proof are correlative notions.  The defeasible presumption that the accused is innocent until proven guilty places the onus probandi on the prosecution.  Therefore, from the fact that the POI is not itself defeasible in a court of law, it follows that neither is the BOP.  Where the initating BOP lies -- the BOP that remains in force and never shifts during the proceedings -- is never subject to debate.  It lies on the state in a criminal case and on the plaintiff in a civil case.  If you agree to play the game, then you agree to its constitutive rules.  Since these rules are constitutive of the game, they cannot be rejected on pain of ceasing to play the particular game in question.

3. But in philosophy matters are otherwise. For in philosophy everything is up for grabs, including the nature of philosophical inquiry and the rules of procedure.  (This is why metaphilosophy is not 'outside of' philosophy but a branch of same.)   And so where the BOP lies in a debate between, say, atheists and theists is itself a matter of debate and bitter contention.  Each party seeks to put the BOP on the other, to 'bop' him if you will.  The theist is inclined to say that there is a defeasible presumption in favor of the truth of theism; but of course few atheists will meekly submit to that pronunciamento.  If the theist is right in his presumption, then he doesn't have to do anything except turn aside the atheist's objections: he is under no obligation to argue positively for theism any more than the accused is under an obligation to prove his innocence.

Accused to accuser: "I don't have to prove my innocence; you have to prove my guilt.  I enjoy the presumption of innocence; you bear the burden of proof." 

Theist to atheist:  "I don't have to prove that God exists; you have to prove that God does not exist.  Theism enjoys the presumption of being true; atheism bears the burden of proving that theism is not true." (This assumes that BOP and DP are legitimately deployed within broadly philosophical precincts -- which I am denying.)

Note that if the theist invokes the above presumption he needn't be committing the ad ignorantiam fallacy.  He needn't be saying that theism is true because it hasn't been proved to be false.  Surely the following deductive argument is invalid:

No one has ever proved that God does not exist
ergo
God does exist.

Just as the presumption of innocence does not entail that the accused is innocent, the presumption of truth does not entail that the proposition presumed true is true.  So the mere fact that I have the presumption on my side does not amount to an argument that what I am presuming is true.  If I have the presumption on my side, then my dialectical opponent bears the BOP.  That's all.

4. Now we come to my tentative suggestion.  There is no fact of the matter as to where the BOP lies in any dialectical context, legal, philosophical or any other: it is a matter of decision and agreement upon what has been conventionally decided.  In chess, for example, the rules had to be decided and the players have to agree to accept them.  No one thinks that these rules are inscribed in rerum natura.  The same goes for BOP and DP. It had to be decided that in court room discourse and dialectic the accused enjoys the DP and the accuser(s) the BOP.

In philosophical discourse, however, there are no procedural rules regarding DP and BOP that we will all agree on. 

For example, according to Douglas N. Walton, ". . . the basic rule of burden of proof in reasonable dialogue is: He who asserts must prove." (Informal Logic, p. 59) That is clearly false.  If I assert that that you left the door open, there is no need for me to prove my assertion.  A proof is an argument having premises and conclusion.  Surely there is no need to argue for matters evident to sense perception.  In fact, it would be unreasonable to do so.  Or suppose I assert the Law of Noncontradiction.  There is no way I can (non-circularly) prove it.  So I cannot be under any epistemic obligation to prove it.  'Ought' implies 'can.'

And how would this work in a dispute between theist and atheist?  I assert that God exists and you assert that God does not exist.  We both assert.  So we both bear the BOP, and we both enjoy DP?  But then BOP and DP have no application in this area.

I have heard it said that the BOP lies on the one who makes a positive (affirmative) assertion.  But surely both theist and atheist make positive assertions about reality.  'Reality is such that God exists.' 'Reality is such that God does not exist.'   Both propositions are logically affirmative.

Suppose our atheist denies God by saying 'God is an unconscious anthropomorphic projection.'  Logically, that is an affirmative proposition.  Will you conclude that the BOP is on the atheist?

Some say that presumptions are essentially conservative: there is a presumption in favor of the existing and the established  and against the novel, the far-out, and what runs contrary to prevailing opinion.  "If it ain't broke, don't fix it."  Suppose I give the following speech:

There is a presumption in favor of every existing institution, long-standing way of doing things, and well-entrenched and widespread way of belief.  Now the consensus gentium is that God exists.  And so I lay it down that there is a defeasible presumption in favor of theism and that the burden of proof  lies squarely on the shoulders of the atheist.  Theism is doxastically innocent until proven guilty.  The theist need only rebut the atheist's objections; he needn't make a positive case for his side.

Not only would the atheist not accept this declaration, he would be justified in not accepting it, for reasons that are perhaps obvious.  For my declaration is as much up for grabs as anything else in philosophy.  And of course if I make an ad baculum move then I remove myself from philosophy's precincts altogether.  In philosophy the appeal is to reason, never to the stick. 

The situation in philosophy could be likened to the situation in a court of law in which the contending parties are the ones who decide on the rules of procedure, including BOP and DP rules.  Such a trial could not be brought to a conclusion.  That's the way it is in philosophy.  Every procedural rule and methodological maxim is further fodder for philosophicalForschung. (Sorry, couldn't resist the alliteration.)

My tentative conclusion is as follows.  In philosophy no good purpose is served by claims that the BOP lies on one side or the other of a dispute, or that there is a DP in favor of this thesis but not in favor of that one. For there is no fact of the matter as to where the BOP lies.  BOP considerations are usefully deployed only in dialectical situations in which there is an antecedent conventional agreement on the rules of procedure, rules  that constitute the dialectical 'game' in question, and  that are agreed upon by the players of the game and never contested by them while playing it.

(Originally posted 25 October 2014)