Why and how does Nagel criticize physicalism and idealism?

Nagel warns of false reductions in attempting to describe reality in increasingly objective terms. Physicalism and idealism are two philosophical ideas that Nagel claims are false reductions because they cannot explain reality without losing either the subjective or the objective view of reality.

Physicalism attempts to describe the mind in terms of scientific laws. It is an aspect of the physical conception of objectivity. Nagel believes that there is a parallel, mental conception of objectivity not solely defined in terms of the physical and chemical workings of the brain.

Nagel's view from nowhere is an attempt to describe reality in both subjective and objective terms, never to lose sight of the realities of the secondary characteristics of smell, taste, feeling and sound that make up our perceptions of the world around us. Our thoughts derived from these perceptions make up a point of view rather different from the physicalist description of the mind. Nagel does not dismiss the fact that the brain is essential to the existence of the mind, but that describing how the brain works will not adequately describe the mind.

Physicalism does away with the perceptual content of the world in much the same way as physics does away with the secondary characteristics of objects. These characteristics are prone to misinterpretation and misunderstanding. This featureless, "bleached out" description of reality within the physical conception of objectivity has removed a fundamental, subjective aspect of everyday reality.

To Nagel the subjectivity of consciousness is an irreducible feature that physicalism, like other reductions functionalism and behaviourism, miss.

Physics cannot describe the subjective character of mental processes such as ideas and feelings. There is evidence that the functions of the brain are strongly connected to mental activity although there has to be a non-physical substance that can support subjective mental states that the brain cannot.

Nagel criticises physicalism further for the false reduction of describing the mind like a biological machine not unlike a computer. Physicalism can never give the whole realistic picture of consciousness. It cannot describe how we think although it can hope to describe the workings of the brain.

Physicalism uses the current paradigms of physics and evolutionary biology to understand things like the mind that Nagel believes are inappropriate paradigms to use. Though he admits that there are no current methods or paradigms that can be used to understand ourselves.

Nagel believes that mental and physical phenomena are properties of some underlying reality, so physicalism will only describe one set of phenomena.

To really falsify physicalism requires that there are things like mental states that cannot be reduced to physical terms. Adrenalin may well be the substance that induces the 'fight or flight' impulse within the body, but what makes one person fearful enough to fight or run may not in another. Also there is still the choice of fighting or running.

This leads to the dual aspect theory that there are non-physical properties of the brain. Possibly a 'world-soul' that can create experiences just as physical objects are created out of matter.

With idealism we move from how we think to what we can think about.

Idealism attempts to describe reality in terms of what can be conceived of. Linguistic idealism claims that reality can only be that that can be understood in terms of words. Reality is only what we can put words to. This reality is mind dependent.

Nagel argues that this is a stronger form of idealism than that of Berkeley. For Nagel, Berkeley made the mistake of confusing the mental representation (of a tree) with the content ( a tree). Linguistic idealism does not suffer from this criticism. Words, however, cannot bound Nagel's universe.

Nagel believes that reality, or a good part of it, may be inconceivable to us or our descendants. That we may not put words to it does not mean it is not there. Essentially reality is mind independent.

To illustrate his view he describes first the disadvantaged people of today. The problem of a blind from birth person conceiving of colour or a deaf person being able to understand the Doppler effects of a passing siren does not mean that sight and sound are unreal.

Nagel's second attempt to illustrate his point of view was that of a population with the mental age of nine. Some of these people may surmise that there are concepts describing realities that they cannot be aware of. A higher being may well understand relativity and other difficult concepts, but that understanding could not be imparted to the nine year olds. A nine year old idealist may claim that there are no words that can translate the understanding

of relativity to the rest. They would be correct. That relativity is a concept that explains a more objective conception of reality is proven. So Nagel turns this argument around by describing us as the nine year olds. Reality could be more than what we can put words to. Reality is mind independent.

To believe that relativity as a concept cannot be improved upon is unrealistic, but that we could have further concepts that describe reality in totality may also be impossible, because of who we are - finite beings.

Essentially physicalism is too objective for Nagel, whilst idealism is too subjective.

I tend to believe that Nagel's criticisms of the current physicalist tradition is well founded. The analogies found in popular science are too mechanistic and apply to a two dimensional, binary world of computation rather than a more rounded account that can describe the formation of ideas and developing conception.

I tend to believe that reality may well be mind dependent, that what we can think of as reality is bounded by our language and that that language may well develop, in much the same way as our minds may develop to encompass a larger boundary of reality. This is not to say that humanity will soon encompass or conceive of total reality, but to put limits on our understanding may impede our objective progress.