## Thursday, September 30, 2010

### Mathematics and Scientific Representation Update

As readers of this blog are already aware, for some time now I have been working on a book called Mathematics and Scientific Representation which aims to say something useful about how mathematics helps in science. This is a project which combines elements of the philosophy of mathematics with the philosophy of science and so will hopefully be of interest to both communities.

I have recently assembled the chapters into what is hopefully their final form. An outline of the project is available in a revised chapter 1. In the next few weeks, I hope to blog through the 12 key claims which I present at the end of this chapter. Comments and links to other ways of exploring these issues are especially welcome.

## Thursday, September 9, 2010

### More on Epimenides

As Jonathan Livengood helpfully pointed out in a comment on my last post, Bayle links Epimenides to the semantic paradoxes in his Dictionary entry for Euclid (1740, although perhaps also in an earlier edition). A modern source cited by Bayle is Gassendi, and when you track down that reference you indeed find a link between Epimenides and the semantic paradoxes:

This comes from p. 40 of the first volume of the Opera Omnia from 1658, which has been scanned and posted online here. I don't know Latin, but the reference to this case as "celebre" suggests that Gassendi does not take himself to be making a new connection.

## Friday, September 3, 2010

As part of a philosophy of logic seminar on theories of truth I have developed an amateur interest in the history of discussions of logical and semantic paradoxes. As is well known, the Liar paradox can be traced to Epimenides and appears in the New Testament:
It was one of them, their very own prophet, who said, 'Cretans are always liars, vicious brutes, lazy gluttons.' That testimony is true. (Titus 1: 10-13, NRSV)
Russell makes allusions to this passage several times, including in "Mathematical Logic as Based on a Theory of Types" (see here.)

Given the discussion of these sorts of paradoxes in by medieval logicians, I was surprised to find this passage in Spade's article on Insolubles in the Stanford Encyclopedia:
One initially plausible stimulus for the medieval discussions would appear to be the Epistle to Titus 1:12: "One of themselves, even a prophet of their own, said, The Cretians [= Cretans] are always liars, evil beasts, slow bellies." The Cretan in question is traditionally said to have been Epimenides. For this reason, the Liar Paradox is nowadays sometimes referred to as the “Epimenides." Yet, blatant as the paradox is here, and authoritative as the Epistle was taken to be, not a single medieval author is known to have discussed or even acknowledged the logical and semantic problems this text poses. When medieval authors discuss the passage at all, for instance in Scriptural commentaries, they seem to be concerned only with why St. Paul should be quoting pagan sources.[5] It is not known who was the first to link this text with the Liar Paradox.
So, was Russell the first to make this link, or was he merely drawing on other sources?

My first thought was that Hegel or some other post-Kantian must have made the link, and Russell is merely repeating it. Through the power of Google Books I was able to find a passage in the English translation of Lotze's Logic:
One dilemma nicknamed Pseudomenos dates from Epimenides, who being a Cretan himself asserted that every Cretan lies as soon as he opens his lips. If what he asserted is true, he himself lied, in which case what he said must have been false; but if it false it is still possible that the Cretans do not always lie but lie sometimes, and that Epimenides himself actually lied on this occasion in making the universal assertion. In this case there will be no incongruity between the fact asserted and the fact that it is asserted, and a way out of the dilemma is open to us (Book II, Chapter IV).
This translation dates from 1884 and seems to be from the second edition of the Logic from 1880. I have not checked the German or the first edition.

It seems likely that Russell read Lotze's Logic, either in this very translation or the original German, as he notes Lotze's Metaphysik in his readings from 1897 and of course discusses Lotze's views on geometry in the fellowship essay. Still, it seems unlikely to me that Lotze was the first person to make the link. Any other candidates or evidence to consider?