Month: June 2011

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 is no judge or tribunal to lay down and enforce rules of procedure.  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 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 he 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.  The reason there is always a definite outcome in chess (win, lose, or draw) is precisely because of those nonnegotiable chess-constitutive laws. 

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 trhe onus probandi on the prosecution.  Therefore, from the fact that the POI is not itself a defeasible presumption 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.

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 thesism any more than the accused is under an obligation to prove his innocence.

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.  This is because BOP is a procedural matter.  If so, then there must be an adjudicator above the fray (i.e., a judge or arbiter who is not party to the dispute) who makes the decision as to where the BOP lies and has the power to enforce his decision.  There must be an arbiter who lays down and enforces the rules of procedure.  But in philosophy there neither is nor can be an above-the-fray adjudicator  whose decisions are unquestionable and backed by the threat of violence.

For suppose I were to try to play the arbiter in a debate between a theist and an atheist.  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 philosophical Forschung. (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 some authority presides over the debate and lays down the rules of procedure and has the power to punish those who violate them.  Such an authority constitutes by his decision the 'fact' that the BOP lies on one side rather than on the other.

It follows from what I have said that if you disagree with me, then neither of us bears a burden  of proving his metaphilosophical thesis.  But this is paradoxical.  For if you disagree with me, then presumably you think that BOP considerations are usefully deployed in philosophy, and that there is a fact of the matter as to where the BOP lies, and that therefore one of us must bear a probative burden.  

Since I don't understand this topic very well, I blog about it.  Nescio, ergo blogo!  Caveat lector!  The following notes are a blend of what I have gleaned from Nicholas Rescher and Douglas Walton and my own reflections.

1. Burden of Proof and Defeasible Presumption are correlative notions.  If there is a defeasible presumption in favor of not-p, then the burden of proof rests on the one who asserts p.  And if p is such that the burden of proof rests on the one who asserts it, then there is a defeasible presumption in favor of not-p.  BOP and DP are two sides of the same coin.

For example, in Anglo-American courts of law there is a defeasible presumption in favor of the innocence of the accused. One is presumed innocent until proven guilty.  This throws the onus probandi upon the state in criminal cases and upon the plaintiff in civil cases.  The presumption of non-guilt induces the burden of proving guilt.

For a second example consider the practice of safety-conscious gun handlers in non-combat situations. Their presumption is that every gun is loaded; this puts the BOP on the one who claims the opposite.  In a combat situation, or just prior to one, however, it is the other way around: the wise soldier does not presume that his weapon is ready to fire; he checks and makes sure.  There is a defeasible presumption that his weapon is unloaded, and the burden is on him to prove that it is loaded.  Either way we have the correlativity of BOP and DP.

This suggests the context-relativity of judgments as to where the BOP lies.

2.  Presumption that p is true is not to be confused with (high) probability that p is true.  If a gun dealer has just received a shipment of  tactical shotguns from Remington the manufacturer, then the probability is very high that none of these guns is loaded.  And yet his safety-conscious presumption will be that they are loaded.  Similarly in a court of law.  The accused is presumed innocent even when the probability of his being innocent is low  or even zero.  (E.g., Jack Ruby's shooting of Lee Harvey Oswald.)

3. Proof  is a logical concept, but burden of proof is not.  Perhaps we could say that BOP lays down a rule of proper conduct in dialectical situations.  The rule pertains to the 'ethics of argumentation.'  The rule is that he who advances a thesis, by so doing, incurs the obligation to substantiate his thesis by adducing reasons or considerations in in its favor, and by answering objections.

4. Accordingly, there is both a burden of proof and a burden of reply.  The proponent of a thesis has the initial burden of defending his thesis.  This remains constant throughout the dialectical proceedings.  But if his opponent lodges a good objection, then the proponent has the additional burden of replying to the objection.  A further complication is that the opponent in the course of objecting to the proponent's contention may make a claim that itself needs defense, in which case the burden of proof shifts onto the opponent in respect of that claim. 

Bearing this in mind, we see the need to nuance the claim advanced in #1 above according to which the onus probandi in Anglo-American law rests on the state or on the plaintiff.  That is true with respect to the initial allegation, but the defense may assume burdens of proof depending on how it builds its case.

5. Presumptions make up the doxastic status quo.  And so it appears that a certain conservatism is inherent in laying the burden proof on those who would defeat presumptions.  This needs to be explored.

6. Wherein resides the rationality of a presumption?  Rescher claims in his book on presumptions that the rationality of a presumption consists in its conformity to a well-established practive, and that it is not a matter of evidence.  This too needs to be explored.

A reader asks about burden of proof in philosophy.  I really ought to have a worked-out theory on this, but I don't.  Here are some very tentative remarks.

1. In the law it is clear where the burden of proof lies: on the plaintiff in a civil case and on the prosecutor in a criminal case.  The party bringing the charge must show that the accused is guilty; the accused does not have to show that he is innocent.  One is presumed innocent until proven guilty.  To be presumed innocent is of course not to be innocent.  It is simply false that one is innocent of a crime unless or until proven guilty.  And to be found innocent/guilty is not to be innocent/guilty.  O. J. Simpson, for example, was found innocent of a double homicide.  But I have no doubt in my mind that he was guilty.  I don't mean that autobiographically as a report on my mental state; I mean the S.O.B. really was guilty.  Agree with me on this or not, you must agree that someone found innocent can be guilty and someone found guilty can be innocent. 

We should distinguish between burden of proof and standards of proof.  In the criminal law, the probative standard for guilt is 'beyond a reasonable doubt,' while in civil cases the standard is less demanding: 'preponderance of the evidence.'

2. In philosophy it is not often clear where the burden of proof lies, nor what our probative standards ought to be.  (What the hell did you expect?)  'Proof' can be used in a very strict way to refer to a valid deductive argument with objectively self-evident premises.  But this is not what 'proof' means in 'burden of proof.'  It means something like: burden of argument or burden of persuasion.   It means that some claims need to be argued for, and some don't.  Or perhaps: there is a (perhaps defeasible) presumption in favor of some claims but not in favor of their negations. 

For example, I would say there is a defeasible presumption in favor of the claim that drinking coffee in moderate amounts carries no health risk for most people.  So the burden of proof would be on a researcher who claims that coffee-drinking causes pancreatic cancer.  And because the evidence that coffee-drinking is harmless is so strong,  the probative bar the researcher must clear is correspondingly high.  The researcher needs to give strong evidence for his claim; the rest of us don't need to do anything.

Now consider the Holocaust denier, the 9/11 'truther,' the Obama 'birther,' and the Osama-was-killed-in 2001 kook.  Clearly, the burden lies on them to make their respective cases, and good luck to them.  The appropriate thing to say to those of this stripe is "Put up or shut up."  That 9/11 was an 'inside job' is a claim of such low antecedent probability that the case for it must be correspondingly strong.

A more philosophical example is provided by my present dispute with Peter Lupu about the modal principle that states that if proposition p is necessary, and p entails proposition q, then q is necessary.  He thinks he has found a counterexample to this principle.  Where does the onus probandi lie, and why?  It seem clear to me that the burden lies on Peter since he is controverting a well-known principle of elementary modal propositional logic.  (See. e.g., K. Konyndyk, Introductory Modal Logic, U. of Notre Dame Press, 1986, p. 32.) The burden does not lie on me since I am invoking a well-established, uncontroversial principle. 

Can we generalize from this example and say that whenever one controverts something well-established and long-accepted one assumes the burden of proof?   I doubt it.  Galileo defied Aristotle and the Church when he made certain empirically-based claims about the moon.  He claimed that the moon was not a perfect sphere.  As the story goes, the Church authorties refused to look through his telescope.  But it is at least arguable that the onus probandi rested on the authorities since they were flying in the face of sense perception.

But I hesitate to say that whenever one's case is based on sense perception one can shirk the burden of proof.

3.  I doubt that there is any criterion that allows us to sort claims that need proof or argument from those that don't.  Or can you think of one?  Some maintain that whenever a person make a claim to the effect that X exists, then the burden of proof is on him.  Well, it is in some cases, but surely not in all.  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.

Others seem to think that whenever one makes an affirmative claim one assumes a burden of proof.  Not so.  'That hillside is studded with Saguaros' said to my hiking companion needs no proof.  I shoulder no probative burden when I make a commonplace observation such as that.

4. Burden of proof and the ad ignorantiam 'fallacy.'  Gun instructors sometimes say that every gun is loaded.  That is plainly false as is stands, but a wise saying nonetheless if interpreted to mean: every gun is to be presumed loaded until proven unloaded.  So if  person A claims to person B that a certain gun is unloaded, the burden of proof is on him to show that it is unloaded; person B does not bear the burden of proving that it is loaded.  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 ~p; therefore p gives us the form of the ad ignoratiam 'fallacy.'  But in this case the appeal to ignorance seem nonfallacious.  Safety considerations dictate a defeasible presumption in favor of every gun's being loaded, a presumption that shifts the onus probandi onto the one who maintains the opposite.

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 or the plaintiff.  In a criminal case the probative bar is set high: the accused has to be shown guilty beyond a reasonable doubt.  Here too there is a legitimate appeal to ignorance: it has not been shown that the defendant is guilty beyond a reasonable doubt; therefore, he is not guilty.

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.  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.

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 loaded, 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 becuase he is making an existential claim; for there are existential claims — I gave an example above — that need no proof.  Nor can you say that the burden rests on the theist because he is controverting the widely-accepted; the consensus gentium is that God exists.

But I suppose you could reasonably say that the burden rests on the theist since he is making a claim that goes well beyond what is empirically verifiable.