dividuated, then so too will a person’s intentions be; and then so will their
intentional behaviour.
A similar point holds in connection with singular thought. Consider the
case where Mary and Joan think, ‘Thattable is greasy’, and each reaches
for a tissue to wipe it. Or consider the case where I and my twin each sees a
cat, thinks, ‘Thatcat is dangerous’, and lashes out at it with a foot. While it
might initially seem that in the two types of case we are dealing with two
instances of the same behaviour (table-wiping and cat-kicking respec-
tively), which should then receive the same (narrow) explanations, in fact
the behaviourscanbe categorised as diVerent. For Mary wipesthistable
while Joan wipesthatone. And Peterekicks Tiddles while Petertwkicks
Twiddles. So if singular thought is relationally individuated, in such a way
as to embrace the actual objects thought about, then actions guided by
such thoughts, under an intentional description, will come out as relation-
ally individuated too. And then the argument above collapses.
Notice, however, that this response by the externalist places questions of
sameness and diVerence of behaviour, and of sameness and diVerence of
psychological explanation, in hock to scientiWc discovery, in a way which
may seem unpalatable. For suppose it had turned out that water (some-
what like jade) is diVerently constituted in diVerent parts of the globe. In
that case Mary, in England, and Kylie, in Australia, might have been
engaged indiVerent behaviourswhen reaching for a glass of water, even in
advance of the discovery of the diVerence. (We assume that the externalist
must say that if water in England is H 2 O, but in Australia is XYZ, then the
word ‘water’ refers to diVerent substances when used by Mary and Kylie
respectively.) And when we explain those behaviours by saying, ‘She
wanted a drink of water’, the explanations would have been diVerent too,
attributing thoughts of a diVerent type. So the question of how many types
of psychological explanation there are depends on the question of how
many types of water (and other natural kinds) there are – which is possible,
perhaps, but somewhat hard to swallow!
People sometimes assume that if content is individuated narrowly, then
we would have to resort to individuatingbehaviourin terms of the bodily
movements involved. But this is not so. There are a variety of ways of
classifying behaviour, depending upon purpose and context. Sometimes
we need to classify behaviour in terms of agents’ intentions,narrowly
construed– as, for example, to distinguish the pursuits of knights in search
of the Grail, alchemists in search of the Philosopher’s Stone, and contem-
porary hunters of the Loch Ness monster, even if all alike are on a
wild-goose chase. Our cat-hallucinator and someone actually confronted
by a fearsome feline may equally run away out of fear of a dangerous cat,
for all that one cannot distance oneself from something which is not there.
Explanation and causation 147