From Key Terms in Philosophy of Mind by Pete Mandik, to be published by Continuum in May 2010 (link to publisher's page).
objectivity, (1) of that which exists, that it exists independently of any one’s PERCEPTION of it or THOUGHT or BELIEF about it. (2) Of that which exists, KNOWLEDGE about it being acquirable via multiple kinds of EXPERIENCE. (3) Of mental states, especially judgments or beliefs, that they are arrived at impartially and do not simply reflect the bias of the judge or believer and, additionally, have their TRUTH-value (true or false) in virtue of factors that have objectivity in sense (1) of the term “objectivity.” All three senses of “objectivity” may be contrasted against correlative senses of SUBJECTIVITY.
Despite sense (3)’s being explicitly about a feature of mental states, senses (1) and (2) have played more central roles in the philosophy of mind. Sense (1) of “objectivity” has played a central role in discussions of REALISM and TRUTH. The classical debate between early versions of MATERIALISM and IDEALISM concerned whether so-called material objects existed independently of anyone’s perceiving or conceiving of them. Related are discussions of the contrast between PRIMARY QUALITIES and SECONDARY QUALITIES, with the former being more objective than the latter.
Sense (2) of “objectivity” and a contrasting sense of “subjectivity” have been central in discussions of phenomenal consciousness (see CONSCIOUSNESS, PHENOMENAL). Some philosophers have urged that WHAT IT IS LIKE to see red or to be a bat is subjective in the sense of being knowable only from the point of view of one who has seen red or been a bat. In contrast, one need not have any particular kind of experience to know about the brain states of a bat or of a person seeing red. It is claimed, for instance, that while a person blind from birth may not know what it is like to see red, everything physical about the brain states of a red-seeing person is knowable by the blind person. (See also FIRST-PERSON; FIRST-PERSON AUTHORITY.)
subjectivity, (1) Of that which exists, that its existence depends on someone’s PERCEPTION of it or THOUGHT or BELIEF about it. (2) Of that which exists, KNOWLEDGE about it being acquirable via limited kinds of EXPERIENCE. (3) Of mental states, especially judgments or beliefs, that they fail to be impartial and instead reflect the bias of the judge or believer and have their TRUTH-value (true or false) in virtue of factors that have subjectivity in sense (1) of the term. All three senses of “subjectivity” may be contrasted against correlative senses of OBJECTIVITY. For further discussion of both subjectivity and objectivity, see the entry on objectivity.