Naming and Necessity

"The second distinction is between those truths we can know a priori, just by thinking about them, and other truths, knowledge of which requires empirical observation and experiment for confirmation. As before, this distinction – between a priori and a posteriori truths – is traditionally illustrated by saying that our logical and mathematical knowledge is a priori, whereas our empirical, scientific knowledge is a posteriori. In short, the metaphysical distinction between what is and couldn’t have been otherwise vs what is but could have been otherwise was thought to coincide with the epistemological distinction between what we can know without empirical confirmation vs what we can know only through empirical confirmation. Why should that be so? Well, that brings us to the third distinction – between analytic and synthetic truths. An analytic truth is a sentence made true simply by what the words mean – bachelors being unmarried, for example. By contrast, a synthetic truth is made true by corresponding to facts in the world. Throughout most of the 20th century this distinction between the meanings of two classes of sentences was assumed to explain the coincidence of the necessary with the a priori, and the contingent with the a posteriori. If a statement is made true by its meaning alone, then of course it would have remained true even if the facts of the world had been different, and of course it can be known without empirical confirmation, since understanding what it means is enough to know that it is true. What Kripke shows in Naming and Necessity is that the difference between the analytic and the synthetic can’t explain this coincidence because there is, in fact, no coincidence to explain. Contrary to what had been assumed, there are necessary truths knowable only by experience – including many important scientific truths – and there are contingent truths that can be known a priori. Moreover, this difference is not reducible to differences in linguistic meaning or convention. The reason this is important is that it falsified an assumption crucial to the self-conception of philosophy that had grown up in the first half of the 20th century – the assumption that philosophical truths are all analytic, necessary and a priori. Kripke’s shattering of this idea brought back something that had been missing from philosophy for a long time. It brought back the idea that things in the world have discoverable essences, which are properties not just physically required but metaphysically necessary for their existence. Some of these properties are discoverable by science. But these may not exhaust the essential properties of human beings. The impact of Kripke’s book was its message that, despite the progress philosophers have made in understanding meaning and language, philosophical knowledge is not limited to that, which means that philosophy must reconnect to the non-linguistic world."