For Grice, the admission that "intensionality seems to be imbedded in the very foundations of language" doesn't preclude "extensionality." ❋ Unknown (2008)
In other words, fully unrestricted composition calls for extensionality, on pain of giving up both supplementation principles. ❋ Unknown (2009)
Second, the extensionality principle is formulated in terms of a two-place parthood relation. ❋ Wasserman, Ryan (2009)
The intuitive idea behind these principles is in fact best appreciated in the presence of (P. 5), hence extensionality, for in that case the relevant sums must be unique. ❋ Unknown (2009)
This principle can be regarded as a strengthening of the familiar set theoretic axiom of extensionality. ❋ Linnebo, Øystein (2009)
Moreover, and independently, if ξ were just overlap, then (P. 13ξ) would be unacceptable for anyone unwilling to embrace mereological extensionality. ❋ Unknown (2009)
The problem, of course, is that the extensionality principle is inconsistent with the constitution view if we assume that coinciding objects occupy the same place at the same time by having all of the same parts at those times. ❋ Wasserman, Ryan (2009)
However, it turns out that this is not generally the case unless one assumes extensionality. ❋ Unknown (2009)
So it is not entirely surprising that as long as proper parthood is well behaved, as per (P. 4), extensionality might pop up like this in the presence of substantive composition principles. ❋ Unknown (2009)
On second thought, however, mereological extensionality is really a double-barreled thesis: it says that two wholes cannot be decomposed into the same proper parts but also, by the same token, that two wholes cannot be composed out of the same proper parts. ❋ Unknown (2009)
This is perhaps even more remarkable, for on first thought the existence of products would seem to have nothing to do with matters of decomposition, let alone a decomposition principle that is committed to extensionality. ❋ Unknown (2009)
That classes have the feature of extensionality is thus derivable, rather than postulated. ❋ Linsky, Bernard (2009)
Concerning the necessity of mereological extensionality, i.e., the left-to-right conditional in the consequent of (27): ❋ Unknown (2009)
To take just one example, consider the set theorist's axiom of extensionality: For any sets A and B, if ❋ Wasserman, Ryan (2009)
(One philosopher who explicitly accepts extensionality but feels uneasy about scattered entities is Chisholm 1987.) ❋ Unknown (2009)
For example, the extensionality theorem of EM, (27), says that composite things with the same proper parts are identical, but in the presence of indeterminacy this may call for qualifications. ❋ Unknown (2009)
The worry about the sufficiency of mereological extensionality, i.e., the right-to-left conditional in the consequent of (27): ❋ Unknown (2009)
And since Lowe (1953) many authors have expressed discomfort with such entities regardless of extensionality. ❋ Unknown (2009)
But their independent motivation also bears witness to the fact that controversies about the necessity of extensionality, and particularly about (28), stem from genuine and fundamental philosophical conundrums and cannot be assessed by appealing to our intuitions about the meaning of ❋ Unknown (2009)
At least, this seems reasonable in the presence of extensionality. ❋ Unknown (2009)
