You're poking at the difference between a type/class/protocol/interface versus an object/implementation. There can be no difference in the type/class unless there's a difference in the objects that constitute that type/class. So, your 2 rats are of a type, implemented by different objects. And your Tiller of Theseus has an invariant type, implemented by variations in 2 objects. Or, said another way, your 2 rats and your 2 tillers have distinct particulars, but identifiable similarities.
On 07/18/2018 08:53 AM, Nick Thompson wrote: > David, and all, > > > > I am overwhelmed (of course) by the diversity and complexity of the answers. > I had expected at most a few answers, highly similar to one another, of the > form, “Nick you idiot….,” followed at most by a couple of sentences. It > seems that I am missing some context that would make the answers seem both > more similar and straightforward. > > > > Allow me to illustrate my confusion with a story, bearing in mind that my > confusion has absolutely no value except in so far as it might provide an > occasion for Wizards of Your Dark Art to come to a consensus amongst > yourselves about how to explain this stuff to us (as Owen so unforgettably > puts it) /citizens/. When I was teaching at Swarthmore in the Sixties there > was a Shop Guy who could design and build ANYTHING. I asked him to build two > model “rats” to illustrate [what later became known as] Supervenience to bio > students. The “rats” were just plywood cutouts of rats, exactly the same on > the surface with, two lights for eyes and three switches. The job of the > student was to use the behavior of the rats (how the lights related to the > switches) to figure out the design of the two rats. Only when they had > committed themselves to a “model” of the rats “insides” were they allowed to > look inside and see how they were actually put together. They all concluded > that the rats > were the same, but of course my rat-maker had used different components and > circuitry to arrive at the same behavior. (I think one was straight logic > and the other involved stepping switches, but don’t hold me to that. ) > > The rats were thus doubly modular; they were made of modules, but, more > important to me at the time, they were modules themselves for the purposes of > demonstrating “rat” behavior. > > > > OK. So the rats’ behavior supervened upon their circuitry. In other words, > there’s more than one way to skin a … rat. If I wanted to demonstrate “rat > behavior”, it made no difference to me which of his two rats I took off the > shelf. This was intended to demonstrate to the student that brain models > lived in the behavior of organisms and that just because somebody said > something about neurons and synapses didn’t necessarily mean they knew > anything about how the brain actually accomplished behavior. But that issue > is for another day. > > > > Here’s another story. Years ago my 1970’s era Troy Bilt tiller began to fail > and I took it to a Guy. The Guy said, yes I can rebuild your engine, pretty > much like new. It will cost you around $400. OR, he said, I can bolt a new > Briggs and Stratton engine on there for 150 dollars. So, of course, I went > for the new engine. When I got my tiller back, it worked beautifully, but it > looked weird. The engine was a funny shape, the color was all wrong, but it > had all the connectors it needed, it responded to all the levers, and it did > the job. Evidently, tiller functioning supervenes upon engine construction. > > > > Now this is how I was starting to think about “objects” in programming. They > were, in effect, black boxes, with stress laid on the intersubstitutability > of different fulfillments of the box. And like any modular system (DNA comes > to mind), modularity is a great spur to creativity, leaving programmers free > to work on better modules knowing that as long as the version of the “object“ > they design (which, say, can work in a greater variety of heat conditions or > uses less power, etc.) is the “same” box, then their work is a contribution > to the whole. This is how I understood DOS utililties and Matlab tools. I > guess, in short, I was thinking of objects as /functionally /defined. This > how I created and used macros in Word. > > > > Some of your responses seemed to confirm my intuition; others seemed to be > totally different. But there seemed to be a consensus among you, leaving me > to believe that I still don’t understand the context in which the term, > “object”, is used that carves it out from the rest of the world for you > Wizards. > > > > Thanks for your intricate and patient replies. -- ☣ uǝlƃ ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove
