Kyle asked:

Nagel says that ‘an organism has conscious mental states if and only if there is something that it is like to be that organism, something it is like for the organism.’ Can you explain what Nagel means by this?

Answer by Peter Jones

As far as I understand him, Nagel means that if someone were to ask an organism with conscious mental states whether it is ‘like’ anything to have those states it would reply ‘yes’. Here ‘like’ should not imply a comparison, as if mental states must always be to like this or like that. They can be like anything at all just as long as they are like something. Is there something it is like to be you? If so, then you are an organism with mental states.

It is a slightly confusing way of using words and it has attracted some criticism in consciousness studies, the phrase ‘something it is like’, but consciousness is a difficult phenomenon to talk about. If we change it to ‘something it feels like’ then this makes more immediate sense, since many philosophers would take feeling as sufficient evidence for consciousness, the latter being necessary for the former. To be consciousness would be to know what it feels like to be conscious. Exactly what it feels like would not matter.