[lit-ideas] Re: Philosophical points
- From: Eric Dean <ecdean99@xxxxxxxxxxx>
- To: <lit-ideas@xxxxxxxxxxxxx>
- Date: Fri, 21 Mar 2008 21:22:51 +0000
Phil Enns, with whom I tend to agree, writes:
"If the word 'mortal' is to tell us something interesting about any particular
example within the set of 'all men', then the sentence "all men are mortal"
cannot be formalized with the proposition "For all x if x is a man then there
exists a time t such that x dies at t". There is of course the obviously
problematic 'there exists', which should be a conversation stopper. Beyond
that, it is difficult to see how picking a highly idiosyncratic 'meaning' of a
sentence (i.e. that mortality refers to a point in time), providing a highly
idiosyncratic formalization (i.e. 'scientific') of that 'meaning', gives one
grounds for deciding whether that sentence is or is not scientific. Put
differently, under such particular conditions, I can imagine ruling out any
sentence as being a scientific hypothesis. After all, what sentence could not
render peculiar 'meanings' that would render them unscientific?"
First, I completely agree that "there exists" is a problematic expression. I
think, though, that Quine's usage is both decipherable and coherent, though I
do have my doubts about the entire program within which that usage makes sense.
The usage derives from the notion that time can be treated, for purposes of
science, as a fourth spatial dimension. In that sense, one can say "there
exists" a time t such that..." in the same way one can say "there exists a
point p such that...". In this usage one can say "there is a time t such that
t is greater than 5:00PM EST on March 21 2008 and the sun sets in Washington DC
at t" and mean something like "the sun will set later this afternoon", tortured
as such a way of saying it might be. In the case of the restatement of "all
men are mortal", this all cashes out as simply meaning that a mortal man will
die some time, surely not a problematic notion on any construction.
While such circumlocutions may usefully (?) make explicit the logical
underpinnings of the mathematics which in turn underpin physics, I certainly
agree that they're of dubious value in the case of "all men are mortal". I do
think, though, that to the extent science should be expressible with a logical
rigor comparable to mathematics (if not entirely resolvable into mathematical
structures), Quine's formalization would qualify as a way of making explicit
the aspects of the logical structure of "all men are mortal" which render it
unfalsifiable, and hence unscientific, at least by Quine's lights.
Next, I don't think Quine's rewrite means that he thinks mortality refers to a
point in time. Here's another way of making the point I think Quine was
making, but referring to a different time:
"For all x, if x is a man then there will be a time t such that if y was the
time x died, then y < t"
For example, I could say about myself, I will have died before the year 2398,
or the year 2400 for that matter. In other words, it just says I'll die
sometime, without getting hung up on there being (today) a particular time at
which I'll die. But Quine's complaint about "all men are mortal" as a
scientific hypothesis would remain for this formalization as well, since there
is still no way to find a case that falsifies the statement (i.e. you'd have to
wait around for all eternity to find one).
Finally I think the there's much confusion generated from the idea that Quine
would have thought his formulation amounted to a formalization of *the entire
meaning of* "all men are mortal." I think he would have seen himself as
singling out a legitimate and meaningful part of the meaning (everyone's going
to die sometime) which might sound like the sort of generalization about which
science might give us useful insight, and then demonstrating that even that
potentially scientific-sounding bit really can't be treated scientifically.
While I don't entirely sympathize with Quine's biases about what constitutes
science, I don't think he's entirely out to lunch about this point, and, as I
said in my first post, so much the worse for science's ability to illuminate
the human condition.
Regards to one and all,
Eric Dean
Washington DC
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