Why do philosophers care about answering question on identity or consciousness?

There is one very general reason and two more specific reasons that philosophers are interested in the question of whether consciousness is identical to a particular bodily state.

The general reason is this: we are interested in knowing what the most basic constituents of the world are, and how they are related. If consciousness is not identical to a bodily state, then wewant to know what sort of thing it is and how it seems to be able tointeract with the body. But if consciousness is identical to a particular pattern of brain waves, for example, then we are justified in thinking that mental states are not something different than physical states and consciousness can be understood through the study of the brain. In short, we want to clarify different categories of existence, eliminating the confusions that result from thinking that there are two (or more) things when there is just one, or thinking that that there is just one thing when there are actually two (or more).

A more specific, existential reason that we are interested in whether consciousness is identical to a bodily state concerns the possibility of life after death. If consciousness is identical to a particular bodily state, then it cannot continue after that bodily state ceases to exist. So those who think that there is life after death must reject the claim that consciousness is identical to a bodily state. (There are physical particles and forces that continue after the death of a particular body, of course, so if consciousness is identical to these particles and forces then it may continue after a particular body ceases to exist. Most identity theories, however, equate consciousness with a brain state.)

There is also a social or ethical reason for being interested in whether consciousness is identical with a physical state of the body. If there is such an identity, then anything that lacks the relevant physical state (a robot, an insect, a Martian, or a cloud of dust) also lacks consciousness, and needn't be treated as though it were conscious. On the other hand, if there is not such an identity, then there could be consciousness in many places we don't expect it to be, and an appropriate sort of humility is called for.

Read another response by Jennifer Church
Read another response about Consciousness, Identity, Philosophy