The Paradigm-Case Argument
In the early days of ordinary language philosophy at Oxford University, and perhaps inspired by the need for "usage examples" to define a term in a dictionary (consider the great OED), some philosophers called for "paradigm cases" to establish the meaning of a word. Understanding a concept, doing "conceptual analysis," then became simply a matter of finding an appropriate paradigm case.

Very early in the development of such paradigm case arguments, "free will" became a paradigm of analysis by finding a paradigm case. Antony Flew found one in the case of a man who marries the girl he wants to marry, under no social pressure.

The "pressure" reference is, of course, to the absence of any external constraints or compulsions that might limit his "freedom of action" or "compatibilist free will."

Flew says

"The clue to the whole business now seems to lie in mastering what has recently been usefully named, The Argument of the Paradigm Case.69 Crudely: if there is any word the meaning of which can be taught by reference to paradigm cases, then no argument whatever could ever prove that there are no cases whatever of whatever it is. Thus, since the meaning of 'of his own freewill' can be taught by reference to such paradigm cases as that in which a man, under no social pressure, marries the girl he wants to marry (how else could it be taught ?): it cannot be right, on any grounds whatsoever, to say that no one ever acts of his own freewill. For cases such as the paradigm, which must occur if the word is ever to be thus explained (and which certainly do in fact occur), are not in that case specimens which might have been wrongly identified: to the extent that the meaning of the expression is given in terms of them they are, by definition, what 'acting of one's own freewill' is. As Runyon would say: If this isn't an x, it will at least (do till an x comes along. A moment's reflexion will show that analogous arguments can be deployed against many philosophical paradoxes.

"What such arguments by themselves will certainly not do is to establish any matter of value, moral or otherwise: and almost every one who has used them, certainly the present writer, must plead guilty to having from time to time failed to see this. For one cannot derive any sort of value proposition: from either a factual proposition about what people value: or from definitions however disguised of the value terms which people as a matter of fact employ."

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The next year Arthur Danto wrote an article, "The Paradigm Case Argument and the Free-Will Problem." He doubted that a paradigm-case argument was useful for the "real problem of free will."
I wish to show that the sort of argument I have quoted does not in fact close the books even on the ancient issue. And I wish to show that ordinary language so construed is simply irrelevant to the celebrated problem of the freedom of the will.
Danto nicely points out that what the (comaptibilist and determinist) philosophers of his time considered the "free-will problem" was not the ordinary language use in this paradigm case.
The occasions on which we might use the expression in ordinary life are really rather special. There is, of course, the reproachful use: Smith has botched his marriage and cries on our shoulder, so we say "Well, you married of your own free-will." We would not say this were we sympathetic with Smith, or felt his problem deeply, or were being paid to listen to him, or blamed his wife. Mainly, however, we use the expression only when someone else has said, or thought, that somebody was forced to do something against his will. "He did it of his own free-will" then serves to deny such an assertion.

It is a characteristic (and perhaps a crucial) difference between ordinary and philosophical denials of free-will that willingness is not a component of the latter. The determinist is surely not arguing the patently false proposition that we always act unwillingly, contrary to our will. But that, I think, is nearly always what we mean in ordinary life when we say that someone did not act of his own free-will. We mean he was forced to do it. Furthermore, we never say, apropos of nothing, that someone did something of his own free-will. Indeed, were someone to tell me that Smith married and add that he did so of his own free-will, I should wonder what he was insisting upon. And I would gather that there was more to the story than I had been aware of. Now if I am correct in all this, then, I think, even if determinism came to be universally accepted, it would leave this part of ordinary language quite unmodified. For people would still have inclinations, would still sometimes be forced to act against those inclinations, would very likely still seek extenuation, etc. Or they would sometimes be released from certain pressures, restrictions, and obligations. So we should still require the expressions we now employ, e.g., "He did it of his own free-will" or "He is free" (i.e., "no longer in conference," "no longer engaged to the girl from Vassar," "has broken the habit," "is out of jail").

Here Danto anticipates Peter Strawson's changing the subject to moral responsibility in 1962
Someone might of course complain, once determinism were universally accepted, that these expressions smack of an old, wrong view of things, that new expressions ought to be found. But what would be the gain? The distinctions would still need somehow to be made. And the point is, the expression "of his own free-will" is used simply to make these distinctions now.
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Chapter 3.7 - The Ergod Chapter 4.2 - The History of Free Will
Part Three - Value Part Five - Problems