logically true (e.g. "no unmarried man is married") and the more dubious ones; sentences like "no bachelor is married". Previously it was thought that if you can prove that there is synonymity between "unmarried man" and "bachelor", you have proved that both sentences are logically true and therefore self evident. Quine however gives several arguments for why this is not possible, for instance that "bachelor" in some contexts mean a bachelor of arts, not an unmarried man. Confirmation holism and ontological relativity Colleague Hilary Putnam called Quine's indeterminacy of translation thesis "the most fascinating and the most discussed philosophical argument since Kant's Transcendental Deduction of the Categories". The central theses underlying it are ontological relativity and the related doctrine of confirmation holism. The premise of confirmation holism is that all theories (and the propositions derived from them) are under-determined by empirical data (data, sensory-data, evidence); although some theories are not justifiable, failing to fit with the data or being unworkably complex, there are many equally justifiable alternatives. While the Greeks' assumption that (unobservable) Homeric gods exist is false, and our supposition of (unobservable) electromagnetic waves is true, both are to be justified solely by their ability to explain our observations. The gavagai thought experiment tells about a linguist, who tries to find out, what the expression gavagai means, when uttered by a speaker of a yet unknown, native language upon seeing a rabbit. At first glance, it seems that gavagai simply translates with rabbit. Now, Quine points out that the background language and its referring devices might fool the linguist here, because he is misled in a sense that he always makes direct comparisons between the foreign language and his own. However, when shouting gavagai, and pointing at a rabbit, the natives could as well refer to something like undetached rabbit-parts, or rabbit-tropes and it would not make any observable difference. The behavioural data the linguist could collect from the native speaker would be the same in every case, or to reword it, several translation hypotheses could be built on the same sensoric stimuli. Quine concluded his "Two Dogmas of Empiricism" as follows: As an empiricist I continue to think of the conceptual scheme of science as a tool, ultimately, for predicting future experience in the light of past experience. Physical objects are conceptually imported into the situation as convenient intermediaries not by definition in terms of experience, but simply