Foulkstown, Ballinure, Thurles, Co. Tipperary
22 October 95
Dear Tom & Jehane
Herewith, as promised, something by way of answering the question about believing nonsense. At least it has something to say about the notion of nonsense that may be helpful in addressing the problem even though it doesn’t itself yet really address it. You will see two things about it - one is that it is by way of introduction to my own (scant) works and brings out how I see one whole way of doing philosophy (the correct one, naturally) as turning on the sense/nonsense axis as contrasted with the Cartesian view of it as a special kind of theorizing in pursuit of a special kind of truth. The other thing you will notice is that I make much use of your notion of incommensurable vocabularies, broadening it perhaps, to present any real language as a congeries of a myriad such vocabularies. The difference being that, unlike you, the incommensurable vocabularies that I am interested in are those that are not rivals. It is the transfers between these non-rival incommensurable vocabularies that I want to say is a source of metaphor and the mistaking of the metaphorical for the literal that is a source of nonsense.
I suspect that I am going to have to make my peace with Tertullian’s Credo quia absurdum before I get any real grip on the notion of believing in nonsense. Incidentally, Jehane, my dictionary gives ‘discordant’, ‘harsh’ and ‘unreasonable’ for absurdus. ‘Offending the ear’ seems to be the root sense - I suppose deriving from the idea of talking like a deaf person talks and from the unjust assumption that a dumb person (as deaf people used generally to be) was ‘dumb’ and without sense. ‘Unreasonable’ is already a transferred sense.
I will be much interested to hear what you think, Tom, of the things I say about Newton and the difficulties that come from the fact that there is no construction that will introduce the notion of time into a mathematical model in the way that Euclid is able to introduce his notions by means of constructions. [The relation of Euclid’s definition of straight line to draughtsman’s practice is something I discovered sometime ago but have done nothing with. In fact all three definitions of straightness that Heath considers become plain when you see the practices that give rise to them. The carpenter sighting along his plank gives us Plato’s ‘That of which the middle obscures the ends’ and the chalk line (mentioned already in Homer) gives the ‘Shortest distance’ definition. It was the genius of Euclid to see that neither of the latter were apt or adequate, and to find one that was.]
I suspect you will agree with my locating one source of nonsense, absurdity or emptiness in the mistaking the function of a model, picture or map and using it in a way not recommended by the manufacturer. Of course, the manufacturer was often not too clear about its correct use either. It’s been a while since I’ve looked at The Copernican Revolution, but my memory is that Ptolemy was not always clear whether he was supplying a ‘Sprirograph’ kit for generating three-dimensional curves or a description or physical realities. It’s hard to know just what to say about Newton, about how much his theology did get tangled with his physics. I think one can argue that one back and forth.
Anyway, you’ll see from that introduction of mine just how far out of step I am with the way philosophy is generally done these days, and I am sure that the pieces collected will call down wrath on my head. Individually, they seem to have been mostly ignored - with the exception of one or two who have had their perspective shifted by one or two of them.
You seem to have had a year of it, Tom, (and, naturally you too, Jehane). I was sorry to hear that you had two cataract operations to face on top of everything else. I hope that by the time you get this they will be behind you and the way ahead will be clear of such things.
Bee and I have not yet settled our plans in detail, but the outlines are that we would like to converge on Massachussetts sometime at the end of the second or beginning of the third week of November. She will be driving a van of some sort up from Virginia and I will be flying in to meet up with her to load up some stuff in Northampton and drive it back down to Virginia to be stored/got rid of in some fashion. We want to get that well done before Thanksgiving takes hold. Thanksgiving itself will be a great gathering of the clans, my son and daughter-in-law down from New Rochelle, Bee’s daughter, now in Roanoke, and two of her brothers in that area as well as her mother. A first meeting for any of the two families.
Thomas S. Kuhn 985 Memorial Drive, Apt. 303, Cambridge, MA 02138-5740
October 31, 1995
I'm just back from a trip to Europe (my first since things fell apart three years ago) to find your letter waiting for me. It is useful, whether to define our differences or reduce them I don't know. In either case, thanks.
I know where your notion of a theory comes from, but it's very different from mine. For me, and for an increasing number of philosophers of science, theories are not propositional, not the sorts of structures that can be true or false. In this respect, they're very much like forms of life which, for the relevant community of believers, they help to constitute. Yes, they do change over time, both historical and individual, but so do forms of life. When that occurs, however, the displaced theory is not rendered false, just out of date, no longer recognizable as a form of life at all. (This is the point at which incommensurability enters.)
Propositions, the sorts of entities which have factual content and can be true or false, have no existence independent of the forms of life which permits their formulation. When you say, "the trainee scientists has at least some independent purchase on the world in which he is brought up," I don't know what you can have in mind. Surely it's the way he's brought up that gives him a world (though not any old world -- just one his predecessors have found viable). His independence is only within the limits that that upbringing allows. It's not, that is, independent of either time or culture. (You say all this in the paragraph where you speak of an "independent purchase" which greatly reinforces my confusion about what you have in mind.)
I agree with you that philosophy is not about matters of fact, but more nearly about necessities. But those necessities are constitutive of forms of life while nevertheless differing from one such form to another. I don't know how to get at them without theories, where by theory I mean the sort of thing Wittgenstein speaks of as a "picture of the world" in On Certainty, §94 (and cf. §92). My theory of kind-terms, for example, will attempt to show both why they must exist in sets that seem to give a God's eye view while being nevertheless subject (in groups, not individually) to change with time. I can't think that you want to exclude a theory of that sort from philosophy.