I would happily have hiven this book 4 stars if it hadn't been for the third lecture - it very nearly provoked a 1 star review. Why?

Let's start from the beginning: Kripke makes a very persuasive argument to the effect that we know named objects simply by their names, rather than via a definite description. Thus, the example that one can know of 'Feynman' without knowing anything about him other than that he is a famous physicist, a description so far from being definite that it could apply to any number of people. So, a name is a 'rigid designator', something we use to point out a particular item, but not itself simply shorthand for a description.

This is all good stuff, though it has the mild flaw that such rigid designators cannot achieve any meaning beyond one individual's mind unless they have some association to a description. For example, if you hear me talking about 'Cicero' without giving any description, then you have heard the rigid designator, but you have nothing to attach it to. You need a description, even if it may change over time, and it may be inadequate, to get some idea of what the rigid designator refers to.

Unfortunately, in the third lecture everything falls apart. First Kripke attempts to argue that 'heat' and 'molecular motion' are necessarily identical. This may be so if you're prepared to attach a description to the rigid designator 'heat', something along the lines of 'the sensation which I feel under certain kinds of sensory stimulation, which can be shown by experiment to correspond with the action of causing mercury to expand and contract'. If you don't have that description, you have two entirely separate concepts: the intuitive sense of 'temperature' derived from sensation, and 'calorific heat', a scientific concept based around mean kinetic energy in ensembles of molecules. The description is what links the two, and so without that description, Kripke's argument collapses. But the description is precisely the thing he refuses to accept. In fact the argument collapses anyway, because in no way is it necessary that calorific heat and the sensation of temperature should be identical.

Now things get worse. In this argument Kripke acknowledges quite happily that 'heat' = 'stimulation of certain nerve fibres'. But then he attempts to argue that while that equation is necessary, the equation of pain with stimulation of other nerve fibres isn't! He commits such open lunacy as the following: '...it would seem that God need only create beings with C-fibers capable of the appropriate type of physical stimulation . . . it would seem, though, that to make the C-fiber stimulation correspond to pain, or tbe felt as pain, God must do something in addition to the mere creation of the C-fiber stimulation; He must let the creatures feel the C-fiber stimulation as pain, and not as a tickle, or as warmth, or as nothing.' But this applies equally well to heat, so why was Kripke happy with that equation?

The problem appears to be a very elementary mistake in modal logic, which I would not have expected of Kripke. Viz, he assumes that any conceivable counter-factual counts as a possible world accessible from this one (e.g. a counter-factual in which I feel pain but my C-fibres are not stimulated). But this is only the case in the strong S5 modal logic. In more realistic modal logics, possible worlds are joined by a complex accessibility relation, such that necessity in a world depends on truth in all worlds accessible from that one, not in all possible worlds. Just because Kripke can imagine such a counter-factual, it does not make it a world accessible from this one.

So, in conclusion: buy it, read it, but don't treat it as holy writ. Personally, I'd stick to Quine.

No, really. Kripke maintains a vigorously-argued and important thesis here: the surprising conclusion that statements involving identity (e.g., when calling something or someone out by name) involve a posteriori necessity. This is quite striking because many have assumed that necessity was somehow substantially correlative with the a priori: but that involves a confusion of metaphysical necessity with epistemological necessity. With that idea in place, Kripke goes on to apply (all too briefly, unfortunately) it in some extremely thought-provoking--nay, well-nigh mind-blowing--ideas about things like natural kinds and the mind-body problem. I just wish he had gone into way more detail on these fascinating issues than the three oral lectures transcribed on these 180 or so pages.

If you're reading this review, you've either a) already read this and I don't have to tell you how unique and important it is, or b) maybe have just taken an undergraduate philosophy course that had some lectures on Kripke, and are thinking about checking out the primary literature yourself. If the latter, do so. You'll be enriched, and you might just be taken on a journey from which you'll never return. Philosophers are still, and undoubtedly will continue for some time, discussing the thesis of _Naming and Necessity_ and its implications for at least philosophy of language and metaphysics, and probably philosophy of mind and philosophy of science as well.