

But why do you characterize this as a "flight of fancy" or a "fantasy"?
While I am unfamiliar with the scientific context here, it appears obvious
that his speculation (for lack of a better or more neutral word) was
at least in significant part a consequence of his knowledge of and acceptance
of current theory coupled with his observations.  It would appear that
something quite rational was going on as he attempted to fit his observation
into that theory (or to tailor the theory to cover the observation).  This
does not seem like an example of what most would normally call a flight of
fancy or a fantasy.


Well, I think someone else in this thread was the first to use the word (also,
"extra-scientific", etc.).  Nor am I prepared to give a general account of
rationality.  In terms of examples, there is some danger of beginning to quibble
over what a "surprising" experiment is, what counts as "surprising", etc.
The same may be said about "logical grounds".  My point is that quite frequently
(perhaps even most frequently) the roots of a new theory can be traced to
previously existing theories (or even to previously rejected hypotheses of
some other theory or domain).  I would offer some rather well known examples
such as Toricelli's Puy de Dome experiment done for the sake of his "sea of air"
hypothesis.  Was this theory (and the resulting experimental test) "surprising"?
Well, given the *prior* explanations of the phenomena involved it certainly must
be counted as so.  Was the theory constructed (and the experiment designed)
out of "perfectly rational grounds"?  Well, there was a pretty successful and
well know theory of fluids.  The analogy to fluids by Toricelli is explicit.
The novelty was in thinking of air as a fluid (but this was *quite* a novelty
at the time).  Was the theory interesting?  Yes.  Was it "new"?  Well, one
could argue that it was merely the extension of an existing theory to a new
domain, but I think this begs certain questions.  We can debate that if you
like.