While I do not have time here to enter into a detailed discussion, I think that in the end the argument is best construed as a challenge to Quines opponents to show how determinate radical translation is possible, given only behavioral evidence, and I think it is fair to say that this challenge has not been met.
Thus I regard Quines initial thesis, the thesis of the indeterminacy of radical translation proper, as reasonably firmly established.
The natural response, from an intuitive standpoint, might seem to be that of course the native speaker means one determinate thing by gavagai, whatever he in fact has in mind, and that the translator is merely unable to tell what that is.
Quines conclusion, however, is much more radical and intuitively paradoxical: insofar as such indeterminacy of translation exists, he claims, there is simply no right answer, no fact of the matter as to what the native speaker really means [WO 26-27, 73].
Each argument is central to the views of the philosopher in question, and each leads to sweeping and, to my mind, highly implausible conclusions concerning the content of our thoughts about the world.
The philosophers in question claim, of course, that these implications should be accepted, but few others have been willing to follow them in this.At the same time, however, there has been no very widespread agreement on where and how the arguments go wrong.My view is that they are best viewed as reductions to absurdity of their premises and of one underlying premise in particular.Consider once more the gavagai example, but now imagine that we are the native speakers, and that someone else is trying to decide between analogous choices in his language for the translation of our locution rabbit.Quine argues that just as we cannot determine on an empirical basis whether gavagai means rabbit, rabbit-stage, undetached rabbit-part, rabbit fusion, or rabbithood, so also the radical translator of our language will be unable to decide in a non-arbitrary way between an analogous set of alternatives.I begin with Quines argument for the famous thesis of the indeterminacy of translation.Though it has, as we shall shortly see, an enormously wider application, the indeterminacy thesis is first developed by Quine in application to the situation of radical translation: the situation in which a linguist is attempting to translate a completely unknown language, unrelated to his own, and is therefore forced to rely solely on the observed behavior of its speakers in relation to their environment.Quines claim, in brief, is that while such a radical translator can perhaps succeed, in principle at least, in translating (i) observation sentences and (ii) truth-functional connectives in a determinate, non-arbitrary way, the possibility of determinate, non-arbitrary translation does not extend to the rest of the unknown language.While the sentences which fall outside these bounds can indeed be putatively translated in a way which will be consistent with all possible behavioral evidence, any such possible translation will, he argues, be only one of indefinitely many different alternatives, all of which are equally satisfactory from a behavioral standpoint and between which only an essentially arbitrary choice is possible.For, it is claimed, the indeterminacy extends not only to our knowledge of the native speakers meaning, but to that meaning itself and even to the state of mind of the native speaker which embodies it.Thus the view seems to be that when the native says gavagai, he means something having to do with rabbits, but no particular, determinate thing: his thought is somehow intrinsically indeterminate between the various alternatives. But the most crucial point is that while Quine develops his argument mainly in relation to the situation of radical translation, he makes it quite clear that its significance is not restricted to that rather unusual situation.