rhythmical sound. But both are equally eVects of the heart. What is the
diVerence? The diVerence is that it is (in part)becausethe heart pumps
blood that the containing system (the living body) continues to exist. If the
heart did not pump blood then the system of which it is a part (the living
organism) could not operate as it does. In contrast, the making of a
heart-beat is not causally relevant to the continued functioning of the
organism. So we could say that the function of a particular belief in
cognition is given by those of its eVects which it is supposed to have, which
partly explain how the cognitive system continues to operate successfully –
for example, not leading to predictions which are falsiWed, or not leading
to actions which fail.
4 Functional-role semantics
Teleological semantics faces pretty severe diYculties. One of these diYcul-
ties is that it does not seem plausible to account for the semantic properties
of thoughts in terms of an historical, or selectionist, notion offunction.We
suggested, on the contrary, that psychology (both scientiWc and, especially,
common-sense) is primarily interested in the present. Our content-based
psychology is concerned with the laws and principles governingpresent
cognitive functioning, not necessarily with the question of how those laws
and principles came to be the way they are. This suggested that the best
way forward for teleo-semantics might be to analyse content in terms of a
notion ofcurrentfunction – where the current function of a property F is
that eVect of F within the system which partly explains the continued
functioning of the system.
But maybe it still remains implausible that all thoughts shouldhavea
function in this sense. For example, the content of my belief that the
universe isWnite does not play any role in explaining why my cognitive
system continues to operate, since the only reason I continue to have it is
that I have not found reason to reject it (it is certainly not something that
I need toact upon!). So what we might then do is thin down the notion of
function still further, in such a way that the function of a state is just its
functional, or causal,rolewithin the system – where to characterise the
causal role of a state is just to describe the characteristic pattern of causes
and eVects which it normally has within the system, without any commit-
ment to the idea that some of the eVects of the state play a role in
sustaining the existence of the system itself. And this is, then, the project
of functional-role semantics.
176 Content naturalised