I’m more than halfway through Ernest Gellner’s Legitimation of Belief. It’s a curious book. It suffers from a certain kind of abstraction that frustrates me about a lot of philosophical works — namely, in a word, the utter absence of the phrase “for example” or anything like it. One gets the sense with a lot of similar works that if they were forced at gunpoint to quote supporting evidence — many kinds of supporting evidence, in keeping with the high abstraction of the points they’re making — the whole edifice would crumble.
To be fair to Gellner, his edifice is quite sturdy. He paints other philosophies with a broad brush, just to understand their outline. He’d rather not linger on their details, because he’s pretty sure he’s fair enough to them at his level of abstraction. And in any case, he’s moving briskly through the last five hundred years of philosophy, and he can’t be bothered to stop and quote each of them.
Gellner has a lot of sympathy for the empiricists. He says that epistemologies generally, empiricism among them, can be viewed in either of two ways: either the positive program describing what the world is ultimately built out of (nothing but atoms and the void, in empiricism’s case), or the negative program that tells us what beliefs we’re not allowed to hold. In the latter case, empiricism tells us to reject those philosophies that ultimately reduce to non-observable phenomena like “the soul” or “the Absolute.” Here it’s worth quoting a characteristically pithy Gellner passage on the inevitability of reductionism and the incoherence of those who reject it:
Reductionism, roughly speaking, is the view that everything in this world is really something else, and that the something else is always in the end unedifying. So lucidly formulated, one can see that this is a luminously true and certain idea. The hope that it could ever be denied or refuted is absurd. One day, the Second Law of Thermodynamics may seem obsolete; but reductionism will stand for ever. It is important to understand why it is so undubitably true. It is rooted, as Kant made so clear, not in the nature of things, but in our ideal of explanation. Genuine explanation, not the grunts which pass for such in ‘common sense’, means subsumption under a structure on schema made up of natural, impersonal elements. In this sense, explanation is always ‘dehumanising’, and inescapably so. This also highlights why the machine ideal of explanation really falls within ‘Copernican’ philosophy [in the Kantian sense], the shift of sovereignty inwards, to man: though its premiss seems to be about the world (‘made up of machines’), not about our style of cognition, there is a reason why the world is made up of machines, and that reason lies not in the world but in our practices of explanation.
The meat of that paragraph — “Genuine explanation, not the grunts which pass for such in ‘common sense’, means subsumption under a structure on schema made up of natural, impersonal elements” — would take a lot of argument to fully flesh it out. Gellner hopes to sink the anchor into your intuition, rather than fully justify the point. This approach makes reading this book frustrating when it’s not exhilirating. He’s roughing out the structure of a philosophy.
But he is an empiricist at heart. In part, that may be because (according to Gellner) empiricism is the only epistemology that anyone has bothered to turn into a rigorous scientific enterprise. Those who operationalized it were the behaviorists. Behaviorism has long since been debunked, most famously by Noam Chomsky in his review of B.F. Skinner’s “Verbal Behavior”. But the point, says Gellner, is that at least it said enough as an epistemology to be testable:
Now the differences between empiricist epistemology and many other kinds is that, on the whole, no one has tried systematically to do for other epistemologies what the behaviourists tried to do for empiricism. It is not so much that empiricism is in some way specially vulnerable to the kind of criticism to which Chomsky subjected Skinner; is is rather, that very few thinkers have rendered other theories of knowledge similarly vulnerable, by making a reasonably sustained effort to use them as the base of a genuinely operationalised explanatory model. Were this done, it is most unlikely that those other theories of knowledge would fare any better. . . .
Now no one has done for Hegel what Skinner has endeavoured to do for Hume, to my knowledge. There is no movement, standing in that relationship to absolute idealist epistemology, in which behaviourism stands to classical empiricism. Somehow, this would not be in the Hegelian style. Idealists do not soil their hands by trying to build precise and ambitious models of their own ideas. They are indeed as undemanding as toddlers. When they use their ideas for apparently explanatory purposes, as when the ‘dialectic’ is said to explain something or other, they easily think away the intrusive hands which really move the wooden toy. They are highly practised at this, and it really does not occur to them that higher standards of explanatory power could be possible or desirable.
Legitimation of Belief has clarified a good bit of Bertrand Russell for me. Early Russell, says Gellner, responded to the Hegelian belief that all propositions are in subject-predicate form. Subject-predicate form does not have the expressive power to encode relations — statements like “Jim is taller than Bob” (a two-place relation, with the places filled in by “Jim” and “Bob.”) Hence Aristotelian logic’s inability to encode certain basic premises led Hegelians to conclude that there was only one subject in the universe. Gellner explains the jump brilliantly:
If the world necessarily has a substance/attribute structure [which is the closest metaphysical equivalent to subject/predicate logic], only two visions of the world appear to be available to us: either only one substance exists, and everything in the world is an aspect or attribute of it; or many substances exist, but each is entirely self-contained, and no one of them can every communicate with any other. (For if such communication existed, it would be reported in a proposition whose structure was not subject/predicate, but relational: for it would report a relation between two substances, whose ontological status is equal. Neither can then be an attribute of the other. Hence the proposition would need two subjects, related not only by a predicate but by a relation. But this possibility contradicts the initial hypothesis, namely that all reality is of the substance/attribute form.)
So if you believe that the structure of sentences has something to do with the structure of the universe, your logic dictates the form of the substance from which the world is made. Russell’s help in developing mathematical logic vastly increased the set of available objects in the universe, and eliminated the requirement that the universe be a single substance — at least, mind you, if you cling to this logicist view of the universe. Gellner seems skeptical that the entire logicist enterprise makes any sense as a positive program. He’s more of a fan of negative epistemologies (filtering out bad ideas) rather than positive ones (dictating the shape of the universe), so in the former sense he has some fondness for the logicist program. He draws this positive/negative distinction repeatedly, and uses it to shine light on one of my intellectual heroes. Here I quote length from his discussion of Karl Popper:
The simplified account of the power of falsifiability has often been challenged. The point is that clean-cut, final, definitive falsifications are almost as hard to come by as ‘verifications’. The existence of an unambiguous instance of a counter-example to a given theory, invariably depends on the tacit or overt assumption of background knowledge which had been assumed in the identification of that sample. That background knowledge is inevitably theory-laden; those theories may also turn out to be false. If they do, the putatively final falsification will turn out not to have been final after all. This is merely an application, to the problem under discussion , of the important philosophic thesis of the ‘impurity’, the theory-saturation, of all ‘experience’.
But the real importance, merit, and above all the historic and social significance of falsifiability, does not really hinge on whether it can be a source of these definitive eliminations . . .
The significance of falsifiability lies elsewhere. If we insist that a theory only deserves respect if it is falsifiable, we force anyone who accepts this criterion, to visualise a world in which the theory can be falsified. And to do this is to impose a most dreadful and extremely salutary humiliation on that theory. What world-visions, ideologies, most characteristically do, is to construct a world within which their own falsification is quite inconceivable and in which the preliminary steps necessary for such a falsification are blasphemous . . . Insistence on genuine falsifiability deprives the theory or world-outlook of this capacity to be a judge of its own truth. The real importance of the criterion lies in this power to take them down a peg.
(internal footnote omitted)
That’s a brilliant, and rather subtle, and it seems to me entirely true distinction: what’s important is not which theories are actually falsified, but rather the set of theories that are too vague to even be subjected to falsification. Yes, it may well be difficult to falsify any actual theories; that makes your own ideology’s lack of falsifiability all the more embarrassing. I wonder whether Popper himself would agree with this. I think he might. The Open Society and its Enemies is a brilliantly prolonged exploration of the difference between negative and positive thought, even at the level of government structure: there’s a difference, says Popper, between maximizing pleasure and minimizing pain. The latter leads to a set of policies that’s more testable and less subject to ideology than the former. Seems as though Popper would agree with Gellner on the broader uses of falsifiability.
If I gave it some more thought, I could probably figure out where Gellner fits in the set of other people I’ve been reading; he’s nestled in there rather comfortably. Offhand, Darwin’s Dangerous Idea seems like the closest match. Both Dennett and Gellner are strongly empiricist. Dennett believes that those who reject natural selection within ethics, art, culture and so forth do so out of a misplaced fear — namely a fear that if we provide mechanical explanations for what lies within man, we somehow strip him of his dignity. This fear is obviously misplaced. It’s just as sensible to believe that man is machine-like because he is made of atoms. I think Gellner would agree with Dennett on this point, and yet every now and again he seems to fall prey to the same fallacy — as when he asks of the line of thought that reached its peak with Wittgenstein, “What is that skeleton of reality, revealed for us by the X-ray of sound logical notation? A curious, aseptic, hygienic, cold world.” It’s aseptic and so forth because it comprises logical atoms (and their substantific brethren) bouncing off of each other like billiard balls. I don’t see why the composition of the universe’s ultimate stuff has anything to do with the warmth of the lives we lead — unless, that is, the logical structure forbids love, generosity, faith and so forth. But is there any reason to believe that it does?
So I reject any philosophy that abandons reductionism out of a desire to save humanity. Humanity can get along just fine, with or without reductionism.