Maverick Philosopher: Strictly Philosophical

Evidence and Actuality: A Modal Punch at W. K. Clifford

W. K. Clifford is often quoted for his asseveration that "it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence."  Now one of my firmest beliefs is that I am an actual individual, not a merely possible individual. A second is my belief that while there is an infinity of possible worlds, there is exactly one actual world and that this world of me and my world mates is the world that happens to be actual.  (Think of the actual world as the total way things are, and of a merely possible world as a total way things could have been.  For a quick and dirty primer, see Some Theses on Possible Worlds.)

But not only do I have insufficient evidence for these two beliefs, it looks as if I have no evidence at all.  And yet I feel wholly entitled to my acceptance of them and in breach of no plausible ethics of belief, assuming there is such a subject as the ethics of belief.

Consider the following argument that I adapt from D. M. Armstrong, who borrowed it from Donald C. Williams:

1. Exactly one of the infinity of possible worlds is actual.

2. This world of me and my mates is a possible world.

Therefore, very probably,

3. This world of me and my mates is merely possible.

This is an inductive argument, but a very strong one.  While it does not necessitate its conclusion, it renders the conclusion exceedingly likely.  For if there is an infinity of worlds, how likely is it that mine is the lucky one?

And yet the conclusion is absurd, or to be precise: manifestly false.  Is it not perfectly obvious that this world of ours and everything in it is actual?  I am convinced that I am actual, and that all this stuff I am interacting with is actual.  I am sitting in an actual chair in an actual room which is lit by an actual sun, etc. 

But how do I know this?  What is my evidence?  There are no facts known to me that are better known than the fact that I am actual (that I actually exist).  So my evidence cannot consist of other facts.  Is it self-evident that I am actual?  You could say this, but how do I know, given the above argument, that my actuality is objectively self-evident as opposed to merely subjectively self-evident?  Subjective self-evidence is epistemically worthless, while objective self-evidence is not to be had in the teeth of the above argument.  No doubt I seem to myself to be actual.  But that subjective seeming does not get the length of objective self-evidence.  I now argue as follows:

4. If it is wrong to believe anything on insufficient evidence, then it is wrong to believe anything on no evidence.

5. I have no evidence that me and my world are actual.

6. It is not wrong to believe what is obviously true.

7. It is obviously true that I am actual.

Therefore, contra Clifford,

8.  There are some things it is not wrong to believe on insufficient evidence.

This is not a compelling argument, but it is a very powerful one.  Not compelling because the Cliffordian extremist could bite the bullet by denying (7).  He might say that the ethics of belief enjoins us to suspend belief on the question whether one is actual.  

Now this is psychologically impossible, for me anyway.  But apart from this impossibility, it is surely better known that I am actual than that Clifford's extreme thesis is true.

There are other obvious problems with the thesis.  Any tyro in philosophy should see right away that it is self-vitiating.  If it is wrong to believe anything on insufficient evidence, then it is wrong to believe Clifford's thesis on insufficient evidence.  But what conceivable evidence could one have for it?  None that I can see.  It is not only a normative claim, but one stuffed with universal quantifiers.  Good luck!  If you say that the thesis needn't be taken as applying to itself, then other problems will arise that you can work out for yourself.  Why do I have to do all the thinking?

An Argument for Necessary Beings

1. A contingent being is one the nonexistence of which is possible, whereas a necessary being is one the nonexistence of which is impossible. (At play in these definitions is broadly logical possibility which is between narrowly logical and nomological possibility.)

2. Framing a definition is one thing, showing that something answers to it is another. Are there any necessary beings? Since a necessary being could be either abstract or concrete, I can show that there are necessary beings by showing that there is at least one abstract necessary being. To convey the senses of 'concrete' and 'abstract' by example one could say that God and Socrates are concrete while the proposition 7 is prime and Socrates' singleton -- {Socrates} -- are abstract. All and only concreta are causally active/passive whereas abstracta are not. Please avoid the mistake of thinking that x is concrete if and only if x is physical.

3. Some truths are necessary, others are contingent. 'I am now blogging' is contingently true: it is true, but it might not have been true. I might have been doing something inconsistent with blogging now, sleeping for instance. By contrast, 'If I am blogging, then I am writing' is necessarily true. To see this, negate the sentence in question. The result is a sentence expressing a broadly logical impossibility: 'I am blogging and it is not the case that I am writing.' Consider also, 'If I am blogging, then it is not the case that I am not blogging.' This too is necessarily true, except that the negation expresses a narrowly logical impossibility: 'I am blogging and I am not blogging.'

I don't see how any reasonable person can deny that there are necessary truths. Another example: '7 is a prime number' expresses a necessary truth. This doesn't just happen to be true in the way that it just happens to be true that there are seven cans of Dr. Pepper left in the reefer. It is necessarily true: true in all (BL)-possible worlds.

4. A truth is a true truth-bearer. Now I don't understand how ink on paper, or chalk on a blackboard, or any physical modification of any physical medium, no matter how complex the modification and how complex the medium, could be true or false. I don't understand how anything physical could, qua physical, be a truth-bearer or truth-vehicle, i.e., an item capable of being either true or false. Marks on paper cannot be either true or false. They just exist. But suppose you think they -- or complex modifications of the stuff between your ears -- can be either true or false. Still, the marked-up paper exists contingently. Consequently, the sentence-token '7 is prime' scratched onto the paper exists contingently. Similarly for anything inscribed in your brain. Your brain and its 'inscriptions' are contingent.

5. But then how could any truth be necessarily true? How could any truth be necessarily true if no truth-bearer is necessarily existent?  There is no possible world in which 7 is not prime, but there are worlds in which there are no material things.  Material things are contingent.  How could the proposition in question be true in those worlds if there is nothing in those worlds to serve as truth-bearer? Let's spell this out.

If an item has a property, then, pace Meinong, the item exists: existence is a necessary condition of property-possession.   So if an item such as a truth-bearer has the property of being necessarily true, then that truth-bearer necessarily exists. For if the truth-bearer is true in every world, then it exists in every world.  Therefore, if there are necessary truths, then there are necessary beings. Now there are necessary truths. Therefore, there are necessary beings. Given that everything physical is contingent, these necessary beings are nonphysical. So they are either mental (accusatives of mental acts) or abstract. For present purposes, it doesn't matter which of these they are. The present point is that there is good reason to believe in (i.e., believe that there are) necessary beings.

6. But I hear an objection coming: An item can have a property essentially without having it necessarily. Thus Socrates is essentially human, but not necessarily human. He is human in every world in which he exists, but he does not exist in every world. So he is essentially but not necessarily human. Why can't the proposition expressed by '7 is prime' be like that? Why can't it be essentially (as opposed to accidentally) true, true in every world in which it exists, but neither true nor false in the worlds in which it does not exist? If this is the way it is, then your argument from necessary truths to necessary beings collapses.

The objector is suggesting that truth-bearers are contingent beings. But this is problematic as Alvin Plantinga argues (Warrant and Proper Function, Oxford UP, 1993, p. 119.) Suppose that truth-bearers are brain inscriptions, and consider the proposition

1. There are brain inscriptions.

(1) is such that it could not have been false. You read that right and I wrote it right.  For in a possible world in which there are no brain inscriptions, there are no truth-bearers, which implies that (1) in those words is neither true nor false, hence not false. And in every world in which there are brain inscriptions, (1) is of course true. So (1) is true in every world in which it exists, and not false in every world in which it does not exist. So (1) could not have been false. But this is bizarre. Surely there might have been no brains and no brain-inscriptions. It is not necessarily true that there are brains. If it is not necessarily true that there are brains, then it is possibly true that there are no brains. Now what is this possibility of there being no brains? It is plausibly identified with the possibly being true of the proposition, There are no brains. But then this proposition must exist in those possible worlds in which it is not true.

Necessitas Consequentiae versus Necessitas Consequentis

Take the sentence, 'If I will die tomorrow, then I will die tomorrow.' This has the form If p, then p, where 'p' is a placeholder for a proposition. Any sentence of this form is not just true, but logically true, i.e., true in virtue of its logical form. Now every sentence true in virtue of its logical form is necessarily true. (The converse, however, does not hold: there are necessary truths that are not logically true.) Thus we can write, 'Necessarily (if p, then p)'  or

1. Nec (p -->p).

The parentheses show that the necessity attaches to the consequence, represented by the arrow, and not to the consequent, represented by the terminal 'p.' (When speaking of conditionals, logicians distinguish the antecedent from the consequent, or, trading Latin for Greek, the protasis from the apodosis.) Thus the above is an example of the necessitas consequentiae. This, however, must not be confused with the necessitas consequentis, which is exemplified by

2. p-->Nec p.

In (2) the necessity attaches to the consequent. It should be obvious that (1) does not entail (2), equivalently, that (2) does not follow from (1). For example, although it is necessarily true that if I will die tomorrow, then I will die tomorrow, it does not follow, nor is it true, that if I will die tomorrow, then necessarily I will die tomorrow. Proving fatalism cannot be that easy. For even if I do die tomorrow, that will be at best a contingent occurrence, not something logically necessitated. (Think about it.)

To confuse (1) and (2) is to confuse the necessity of the consequence with the necessity of the consequent. This is an example of what logicians call a fallacy, i.e., a typical error in reasoning, and in particular a modal fallacy in that it deals with the (alethically) modal concepts of necessity and possibility and their cognates.

Class dismissed.

Closer to the Grave, Further from Birth

With every passing day we are closer to becoming grave meat and worm fodder. Or dust and ashes.  That’s the bad news. The good news is that, with every passing day, one more day has been taken up into the ersatz eternity of the Past and Unalterable.

The medievals spoke of a modality they dubbed necessitas per accidens. Socrates drank the hemlock, but he might* not have: He might* have allowed his friends to arrange his escape from prison. So the drinking was logically contingent. But he did drink the poison, and once the drinking  occurred, that fact became forevermore unalterable, and in this sense accidentally necessary.

There is a certain consolation in the unalterability of the past. The old look back upon a sizeable quantity of past and see that nothing and no one can take away what has happened to them and what they have made happen. All of it is preserved forever, whether remembered or not. The terrain of the present may shift and buckle underfoot as one looks to a future for which there is no guarantee. But the past and its accomplishments are in one's sure possession, proof against every threat. It is curious that the mere passage of time should transmute the base coinage of temporal flux into the gold of an ersatz eternity.

Unfortunately, the treasures of the past are preserved in a region both inaccessible and nonexistent -- or should I say next to nonenexistent?  You will thus be forgiven for valuing  the gold in question no higher than iron pyrite.

And herein, in this hesitation, lies the riddle of the reality of the past. On the one hand, the present alone is real, and what is no longer is not. On the other hand, the past is not nothing. Surely it has some sort of reality, and a reality ‘greater’ than that of the merely possible. Kierkegaard existed and so did Regine Olsen. Their engagement existed and so did its breaking off. But their marriage did not exist: it remains a mere possiblity, unactualized and indeed forever unactualizable. Its time-boundedness makes of this mere possibility a present impossibility. Now what is the difference in ontological status between the mere possibility of their marriage and the past actuality of their break-up?  The latter is more real than the former, though both, in another sense, are modes of unreality.

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*These are nonepistemic uses of  'might.'