Lewis, "Languages and Language"
Lewis's "Languages and Language" as a way of
connecting intensional truth-condition theories (which regard a
language as an abstract object that we can discuss using
set-theoretical apparatus) with Gricean theories of languages as social
The connection, as Lewis sees it: a language (in
the abstract sense) is used by a population if and only if there is a
convention of truthfulness and trust in the language in that
population. (Truthfulness in a language means attempting, by and large,
to utter only sentences to which the language assigns, as intensions, a
function whose value at the world of the utterance is "True." Trust in
a language means that when you hear someone else make an utterance, you
believe (by and large) the intension that the language assigns to the
So: for a population P to use a language L is for
there to be, in P, a convention of truthfulness and trust in L. But
what is a convention? In short, "Conventions are regularities in
action, or in action and belief, which are arbitrary but perpetuate
themselves because they serve some sort of common interest" (p.
164). In more detail:
There is a regularity R of the appropriate kind
in P. (In our case, a regularity of truthfulness and trust in L.)
Everyone believes that everyone else acts in
accordance with the regularity.
There is a general preference for general
conformity to R.
The fact that this regularity obtains gives
individuals a reason (in conjunction with their other goals) to
continue acting in accordance with the regularity.
There are other possible regularities that
could in principle work as well as the actual one, if they were
followed as widely.
All the above facts are "common knowledge," in
the sense that everyone knows them, and everyone knows that everyone
knows them, etc.
- You should be able to explain Lewis's account of convention, and
explain how it applies (a) to nonlinguistic conventions, e.g.
driving on the right, and also (b) to the linguistic conventions
that are Lewis's chief interest in the essay.
Last update: April 27, 2010
Curtis Brown | Philosophy of
Language | Philosophy Department
| Trinity University