There's one type of reaction that really frustrates me. It consists of anything along the lines of, "That's a good theory but it won't work in practice."
It doesn't frustrate me that the speaker doesn't think the subject of their criticism will work in practice. That's a matter for rational debate. It frustrates me that in uttering such a statement they have both perpetrated a contradiction and insinuated that their adversary believes one.
It is a contradiction, to my mind, because the only measure of a theory must be its efficacy in practice. A theory that does not work in practice is simply not a good theory.
So the contradiction that the speaker has perpetrated is in admitting that they think the theory is good even while they expect it to fail when put into practice. The speaker is evading either their adversary or their peers—their adversary if they truly believe that the theory is wrong but are afraid to say so—their peers if they truly believe that the theory would work in practice but are afraid to stand up for it.
But the even more insidious side of the statement is the insinuation that one's adversary actually believes the contradiction. Statements of this kind typically carry the implication that it is simply obvious that the theory in question would not work in practice. The speaker attempts to disarm the theory's advocate by suggesting that they persist in promoting the theory even in the supposed light of its obvious flaws.
I, for one, only promote theories that I sincerely believe do or can work in practice, theories that are consistent with reality. I happen to be a fairly abstract-minded person, so I've heard this kind of reaction all too often. So please do me the courtesy of checking your premises before accusing me of promoting an impractical theory. If you believe a theory to be impractical, don't be afraid to say it's a bad theory. If you consider the theory to be good, don't be afraid to put it into practice. §
Copyright 2003 by Justin T. Sampson