Talk:Indiscernibles

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Mathematics rating:	Stub Class	Mid Priority	Field: Foundations, logic, and set theory
Please update this rating as the article progresses, or if the rating is inaccurate. Click to show/hide comments. Please add to or update the comments to suggest improvements to the article. Geometry guy 20:16, 21 May 2007 (UTC)

[edit] comments

I think the reference to the "Identity of indiscernibles" is misleading.

The point of the idea is not that members of a set I can not be differentiated.

The point is that if any two tuples from I have the same length, and the same Delta_0 type for some (intuitively small) set Delta_0 of formulas, then they also have the same Delta_1 type, where Delta_1 is some intuitively larger set of formulas.

It is usually assumed that Delta_0 is either {x=y} (in which case I is an indiscernible *set*) or {x < y} (in which case I is an indiscernible *sequence*). The larger set Delta_1 is taken as L in most cases.

Thus to compare a set of (mathematical) indiscernibles to a (philosophical) collection of indiscernibles is not correct, because the latter notion is of a group which is in principle indifferentiable, whereas in the former case the set may be highly non-homogeneous with respect to Delta_0.

Hunter

Also, "indiscernible" is misspelled as "indiscernable".