In 1952, having for the first time to give a lecture in Madrid, I said somewhat dejectedly to the able and witty young man entrusted with the tedious task of revising the Spanish of my text that I found my lecture didn't amount to much: it was but a long paraphrase of one single idea. Perhaps I hoped for an enthusiastic protest on his part. But he only offered as solace the terse remark: ‘Well, I have heard many a lecture that didn't contain even one single idea’.

The right to privacy is one of the rights most widely demanded today. Privacy has not always so been demanded. The reasons for the present concern for privacy are complex and obscure. They obviously relate both to the possibilities for very considerable enjoyment of privacy by the bulk of people living in affluent societies brought about by twentieth-century affluence, and to the development of very efficient methods of thoroughly and systematically invading this newly found privacy. However, interesting and important as it is as a socio-philosophical inquiry, the concern of this paper is not with why privacy has come to be so highly prized, but rather with whether it is rightly prized, and if so, when and why. This means that my concern will be with what privacy is, what is its domain, whether there is a right to privacy, and, if so, whether it is an ultimate, basic, albeit, a prima facie right, or simply a conditional right.

We already have a distinction between the intension and extension of (linguistic) terms. This is not simply the distinction that is operative in philosophy of mind, body, and action. There, the concern is with things, and with a physicalistic or a mentalistic account of them. The physicalist says he supports an ‘extensional’ analysis of things, the mentalist an ‘intensional’. So, the physicalist says that, in the end, only ‘the extensional language of physical science’ will do in ontology. But, associating this physical-mental dichotomy with the intension-extension distinction as applied to terms is misleading. The ontological issue is obscured by the association. An ontologist wants, like Spinoza or Berkeley, to know whether things are extended or not, and in what respects. This question makes central the concept of space, or more generally of ‘field’, ‘domain’. Unfortunately, the same word ‘extension’ is used also for the spread or location of a thing in space. To dissociate the extension of a term, a logical notion, from the ontological notion of the spatial status of a thing, I introduce the new word ‘extention’. This coinage correlates, not with the ‘intension’ of terms—the logical correlate of ‘extension’—but with ‘intention’, a word that fortunately already has common currency, and reeks with connotations that have logical ties with ‘consciousness’. So, from here on, we have two dichotomies: intension-extension applying to terms, and intention-extention applying to things. Since terms are things, both sorts of considerations are relevant to them, the logical one and the ontological. Only the latter applies to, say, stones or persons, since these are not linguistic terms. (They may be terms of various relations.)

Philosophy, according to a prominent conception of its nature and method, consists primarily of conceptual or linguistic analysis. Because the relations between concepts are logical, and because the propositions which express them are necessary, philosophy is taken to be an a priori activity.

I. It is a necessary condition of the truth of ‘I raised my arm’ that my arm rose; but it is not a sufficient condition. Is there some further necessary condition which, when conjoined with the condition that my arm rose, does give a sufficient condition of the truth of ‘I raised my arm’?

It verges on the platitudinous to say that Wittgenstein's own treatment of the question of a private language has been almost lost to view under mountains of commentary in the last twenty years—so much so, that no one with a concern for his own health would try to arrive at a verdict on the question by first mastering the available discussion. But a general acquaintance with the commentaries indicates that opinion on the matter can be roughly divided into two categories: that of the Old Orthodoxy (both defenders and attackers of Wittgenstein are included), most recently represented by Robert Fogelin in his book Wittgenstein; and that of what may be termed the New Guardians of the Wittgenstein Tradition, apparently based in Oxford and headed by Anthony Kenny, who in his book Wittgenstein has proposed a new account of the argument of Philosophical Investigations §§256–271. The important difference between the old and new orthodoxies will be considered later.