Grice on =, and izzing and hazzing

by JLS for the GC

Jones in "Identity and predication", this blog:

"[W]e must suppose that equality is to be some new primitive notion, not a predicate.Is there anything in Grice to corroborate this inference, or any discussion of whether Pegasus=Pegasus?"

I wonder. In a way, it relates to Aristotle. As Jones is well aware, Grice had problems with Aristotle on izzing and hazzing. I forget about Code's reformulation, but I think in Grice's "Aristotle on the multiplicity of being", Grice has

"I" as

a dyadic predicate indeed, for "Is", "Izz", or "Izzes"

I(x, x)

x izz x.

So, Grice must have thought about those things!

I'm less sure I understood Grice's convoluted way to introduce = in the first place in "Vacuous Names". He seems to be wanting to do that via a second-order version of the system, first. Let me see if I find the page. It seems to be p. 133.

He writes:

"In a CLASSICAL second-order

predicate calculus"


--- at this point one wonders if Stuart Brown is not right that Kripke was Grice's main influence!

Grice goes on:

"one would expect to find that the

formula

(F)Fa ) Fb

-- or the formula

(F(Fa iff Fb)

is a definitional substituend

for, or at least is equivalent

to, the formula

a = b."

----------

Nothing is said about = being a reflexive predicate at that point. Only that two items are identical, if, by Leibniz's law, they are indiscernable.

I can't see who suggested JUST the horseshoe. It seems 'iff' IS necessary.

This may relate to Jones's commentary above. Or not!