Fodor in The language of Thoughts while discusses some aspects of the theory of mental processes, introduces two kinds of reductionisms: behavioural reductionism and physiological reductionism. Either of these two, as he claims, departs psychology from studying its subject matter that is mental phenomena. However, he expresses that he is a physicalist. The first reduction is imposed by ‘logical behaviourism’. In this reduction, mental phenomena have no distinction from behavioural events; in other words, psychology can provide acceptable accounts only if they refer to the effects of environmental variables. Fodor, while claiming that many other psychologists do have similar findings, expresses that he finds this reduction unacceptably limiting. He contends that it is undisputable that internal states of an organism have some sorts of causation on its behaviour. It means the claim of the logical behaviourism that the internal states have no causation on behaviour is counterintuitive. Alternatively, a psychologist can acknowledge that organic processes cause one’s behaviours as long as limiting the processes to the organism’s physiological processes that can be reduced to the organism’s nervous system. This notion leads us to the other kind of reductions: physiological reductionism. (Fodor 1975)
Fodor expresses that either way, behavioural or physiological reductionism, psychology has no subject matter except what it borrows from neurology or physiology. He, while rejecting these reductionisms by introducing them as a false dilemma, claims that behaviours of an organism can be sufficiently exhibited by its internal states. He upholds that there is no convincing reason for psychological laws to be reduced to and replaced by physiological and neurological laws.
To criticise the physiological reductionism, Fodor express that in positivistic views there is a thesis asserts that in the long run theories of other special sciences will be reduced to physical principles. He adds that some scientific successes, such as the reduction of the theory of heat and the chemical bonds to the molecular level, are being used as evidence to support this empirical thesis. However, this hypothesis cannot be proved philosophically by using merely these few achievements in science. It means that the notion of this view that ultimately only physics’ laws will hold cannot be induced simply from past successes in reducing some special sciences into physics. (Fodor 1975)
Fodor asserts that although many philosophers believe that as every event and phenomena in every science ultimately is a physical event and obeys physical laws, then it is acceptable to reduce that science to physics. In his view, those philosophers do not differentiate between stating that the laws of special sciences are reducible to the laws of physics, and stating that physics is the only basic science. In other words, ‘reducibility’ to physics became a criterion for ‘acceptability’ of a special science. Ironically it means that the more a special science is successful the closer it is to the disappearance. Fodor asserts that believing so is a considerable fallacy and is not plausible. He claims that believing in ‘the generality of physics’ is not as strong as stating ‘the unity of science’. (Fodor 1975)
He challenges the notion of reducibility of psychology to physiology and physics by trying to refute that “the subject matter of psychology is part of the subject matter of physics.” He formulates the necessary and sufficient condition for reducing the laws of a special science to physics as the necessity of the existence of a ‘bridge law’ to which the antecedent and consequent formulae - in the special science - must be able to be reduced. Fodor then tries to interpret this formulation and to show the shortcomings of it. He argues that this formulation can be interpreted in two ways: to express event identities and to express property identities. Believing in event identities leads to ‘classical reductionism’ or ‘token physicalism’ as Fodor calls it. This kind of reductionism claims that every event in the special science is a physical event.
However, Fodor reconciles between reductionism and physicalism and remains a physicalist but not a reductionist. He provides three insights to show that the notion of claimed physicalism is much weaker that what is used to sound. First, it is not materialism in its strong sense. It means that it is necessary to be a materialist in order to be a token physicalist. Second, token physicalism is not as strong as type physicalism. While the latter entails the former, token physicalism does not implicate the type physicalism. It means the identity of the properties of two events is not guaranteed even in the presence of the contingent identity between them. Third, reductionism is stronger than physicalism, and although it is a sufficient condition to hold token physicalism, it is not a necessary condition. It means that reductionism cannot be deduced from token physicalism. (Fodor 1975)
Following similar arguments, I do agree with Fodor that non-reductionism and physicalism are reconcilable. In addition to Fodor’s arguments, I challenge the notion of reductionism by considering physics incapability to be the ‘one and only one’ science we need. Physics in itself has no unified system of laws, and there are some areas in physics that their specific laws do not apply to other areas and vice versa, e.g. the laws of quantum mechanics do not apply to non-subatomic particles although those particles are made of the same kinds of subatomic particles. In other words, at least there are two sets of laws that have to be utilised to interpret the dynamics of a specific physical object and they cannot be replaced with or reduced to the other one: quantum mechanics and laws of classic mechanics.
So as an analogy, although subatomic particles consist of non-subatomic particles, their dynamics -as long as their motion is considered - have to be interpreted by classic mechanics or the laws of general relativity theory. One may object that the ‘theory of everything’, once discovered and proofed by evidence, can be a possible rejection to the refutation mentioned above to reductionism.
However, I am a physicalist but not in the same sense that Fodor is. Although all of the natural, including behavioural and psychological, events fall under the physics’ laws umbrella, other sets of laws are necessary to interpret the nature of events in other layers, similar to what I have discussed earlier about classical mechanics and quantum mechanics. These laws can be, but not limited and bound to, psychology’s laws.
Fodor, Jerry, The Language of Thought. New York: Crowell, 1975.