Philosophers are all too familiar with the standard epistemological worry
that our belief that feelings and emotions lurk behind the outward
behaviour of others cannot be justified. Yet there is a more fundamental
puzzle about other minds, which asks: How is it possible for us to have
developed psychological concepts that apply to both ourselves and others at
all? This latter sceptical problem has become known as the conceptual
problem of other minds. It is a conundrum precisely because the two most
natural ways of addressing it are doomed to failure.
For example, on the one hand, if we learn our psychological concepts
of experience by making essential reference to our own experiences then it
is logically impossible to apply the very same concepts to others. The
problem is that any attempt to do so would require reconceiving what is
essential to concepts of experience; that is the idea that experiences have an
essentially subjective character. Given this, the mere fact of others being
'other' makes ascribing experiences to them a conceptual impossibility.
Following this line of thinking to its natural solipsistic end, if this were the
basis of our concepts of experience then the only ones I could understand
would be my own. It would be literally inconceivable that experiences,
other than mine, could even exist.