Ostensive Definitions
The great Wittegenstein went on record to say that ostensive definitions are, to put it in vernacular, no good. It's part of his famous private language argument. His argument goes something like this: If I point to a wooden chair, a wooden ladel, a wooden toy, and say "wood", a listener could easily mistake "wood" to mean the color brown (wood is brown). Ostensive definition fail!!
To refute Wittgenstein's argument is simple.
Consider, lowercase letters to represent qualities like color, hardness, weight, etc and uppercase letters to represent objects.
My aim is to ostensively define the quality w.
Suppose there are now 3 objects A, B, C with the following qualities:
A: a, f, w
B: i, o, w
C: w, y, z
I can do it rather easily using the following procedure:
w :point: A
w :point: B
w :point: C
There's one and only one quality common to the set of objects {A, B, C} viz. w. No confusion can arise.
Conclusion
Ostensive definitions are possible (pace Wittgenstein)
QED
To refute Wittgenstein's argument is simple.
Consider, lowercase letters to represent qualities like color, hardness, weight, etc and uppercase letters to represent objects.
My aim is to ostensively define the quality w.
Suppose there are now 3 objects A, B, C with the following qualities:
A: a, f, w
B: i, o, w
C: w, y, z
I can do it rather easily using the following procedure:
w :point: A
w :point: B
w :point: C
There's one and only one quality common to the set of objects {A, B, C} viz. w. No confusion can arise.
Conclusion
Ostensive definitions are possible (pace Wittgenstein)
QED
Comments (7)
The OP is directed at the subargument of Wittgenstein's PLA (private language argument) where he goes on to say definitions are impossible for definitions build up from ostensive ones, but ostensive definitions are plagued by ambiguity, as outlined in the OP.
Citation, if you would.
[quote=Wikipedia]It might be supposed that one might use "a kind of ostensive definition" for S, by focusing on the sensation and on the symbol. Early in The Investigations, Wittgenstein attacks the usefulness of ostensive definition.[7] He considers the example of someone pointing to two nuts while saying "This is called two". How does it come about that the listener associates this with the number of items, rather than the type of nut, their colour, or even a compass direction? One conclusion of this is that to participate in an ostensive definition presupposes an understanding of the process and context involved, of the form of life.[8] Another is that "an ostensive definition can be variously interpreted in every case".[/quote]
Turns out the quote you cite was inserted (begun) by yours truly, back in 2006.
Watch how any very young kid learns the definition of words. The parent points at a brown wood table and says "table." Points at a brown plastic table and says "table." Kid points at brown car and asks "table?" Parent points at brown car and says "not table." And so on.
With enough examples of what is a table, and enough examples of what is not a table (which is my addition to the examples in the above posts), you get a definition of what a table is.
Ostensive definitions are what our language foundation is based on.
So memory skepticism is all there's to Wittgenstein's PLA? I though he'd seen other issues, one of which I presumed, not wrongly it turns out, was that ostensive definitions, something's off about them.
Quoting Banno
:up: