Referee-artikkeli Paavo Pylkkänen Cognition, the implicate order and rainforest realism It is my proposal that future cognitive science needs to be developed in the context of a general scientific world-view that is based upon contemporary physics. It is within such a general world- view that the special sciences studying the mind (psychology, AI, neuroscience etc.) need to find their proper place, and will hopefully find new avenues for progress when doing so. One research programme which has attempted to articulate such a new worldview is due to the physicists David Bohm and Basil Hiley. They have developed both a general “implicate order” framework as well as a more specific “ontological interpretation” of quantum theory. Both schemes involve radically new ideas and concepts, which also promise to open up new possibilities for understanding the place of cognition and consciousness in nature. Introduction science. In particular, and as already hinted One question that has been underlying my above, one needs to ask to what extent cogni- research is what kinds of assumptions about tive science presupposes the worldview of the nature of the physical world there are in classical physics, and how this may influence cognitive science and how such assumptions its theories. Further, one can ask whether it is might reveal themselves in the theories pro- justified to rely on classical physics assump- posed in cognitive science. For example, the tions as fundamental, given that physics itself traditional view of cognition as mechanical has given up classical physics as fundamen- symbol manipulation is very much in har- tal and sees it instead as a limiting case or mony with the spirit of classical physics, for as a framework that only works in a given manipulable symbols are typical things of domain. And finally, the interesting question the macro world. Also, connectionism and is whether we might be able to explain and dynamical systems theory often employ mod- understand the features of the mind – and els relying on differential equations that are especially its relation to matter - better in a deterministic and are in this sense developed framework that is based upon the new, more in the spirit of classical physics. However, accurate developments in physics. it is not at all obvious that central aspects of It is my proposal that the future cognitive human cognition – such as creative insight or science needs to be developed in the context conscious experience – are phenomena which of a general scientific worldview that is based can be explained in terms of mechanistic upon contemporary physics. It is within computation or dynamic evolution embedded such a general worldview that the special in a classical physics framework. sciences studying the mind (psychology, AI, Physics has changed radically in the course neuroscience etc.) need to find their proper of the 20th century, and these changes imply place, and will hopefully find new avenues the need to change our overall scientific for progress when doing so. One research worldview. Such changes in the general programme which has attempted to articulate worldview in turn usually imply the need to such a new worldview is due to the physicists rethink the nature and status of more specific David Bohm and Basil Hiley. They have theories, such as those central in cognitive developed both a general “implicate order” 74 2/12 framework as well as a more specific “on- Einstein who felt that a fuller and possibly tological interpretation” of quantum theory. more deterministic description should be Both schemes involve radically new ideas possible. A significant suggestion to this and concepts, which also promise to open up direction was made by Louis deBroglie in new possibilities for understanding the place 1925 and especially by David Bohm, who of cognition and consciousness in nature. in 1952-inspired by his many discussions Within philosophy, a particularly intense with Einstein-re-discovered independently attempt to develop a new worldview has in deBroglie’s earlier approach and gave a fuller recent years been made by James Ladyman and more coherent presentation of it. and Don Ross in their 2007 book Every Although initially almost ignored, the Thing Must Go: Metaphysics Naturalized. deBroglie-Bohm approach has received in- In this article I will briefly describe some key creasing attention and approval in recent features of these research programmes and decades, due to the efforts of such leading sketch tentatively how they might change our physicists and philosophers as John Bell, picture of cognition in the future. David Albert, Sheldon Goldstein, Antony Valentini, James Cushing, Arthur Fine, and Getting clear about quantum Hilary Putnam (see Goldstein 2009, which theory: the ontological includes a historical discussion and also con- interpretation siders the criticisms against the approach). Let us first see what cognitive science might What is potentially particularly important learn from Bohm and Hiley’s ontological for the future of cognitive science is Bohm’s interpretation of the quantum theory (for an and his long-time colleague Basil Hiley’s extensive presentation see, Bohm & Hiley extension of Bohm’s original 1952 onto- 1993). For our present purposes what is par- logical interpretation. According to the usual ticularly interesting about this interpretation interpretation of the quantum theory the wave is that it suggests that something analogous to function is often said to describe not a quan- information plays an active role at the level of tum system directly but rather our knowledge fundamental quantum processes. Bohm him- of the quantum system to be observed (typi- self felt that this idea of active information is cally in terms of probabilities). In contrast, relevant to broader philosophical issues, such Bohm and Hiley were suggesting that the as the relationship between mind and matter wave function describes an objectively real (Bohm 1990). To understand this suggestion field, guiding a particle such as an electron. better let us briefly consider the ontological As a new development, they were drawing interpretation of quantum theory. attention to the striking fact that according When quantum theory was first interpreted to the mathematical description favored by in the 1920s, it was typically assumed that Bohm, this field does not push and pull the individual quantum processes (e.g. the de- particle mechanically, but rather it is only the cay of a radioactive atom) are inherently form (second spatial derivative) of the field indeterministic, and that it is not possible that determines its effect on the particle. They to provide an unambiguous model of a suggested that what is going on is that the single quantum system, such as an electron. quantum field encodes information about the Instead, it was either said that we must not whole environment of the particle (e.g. slits) try to picture the electron at all, or else that – the field literally in-forms or puts form into we in some situations may describe it as a the motion of the particle. wave, and in others as a particle (this is the The proposal is radical, for they are in ef- mysterious “wave-particle duality”). Since fect suggesting that this type of information the 1920s, there were also critics such as ought to be acknowledged as a fundamental 75 2/12 – perhaps the fundamental – category of multidimensionality of the many-body wave physics. Indeed, they wrote in 1983: “The function. (It is characteristic of quantum notion of a particle responding actively to theory that every interpretation needs to make information in the [quantum] field is … far some strange assumption(s), and then tries to more subtle and dynamic than any others that avoid some even more unsatisfactory features have hitherto been supposed to be fundamen- with the help of this assumption. This is one tal in physics” (Bohm & Hiley 1983). way of trying to make sense of something In my view Bohm and Hiley’s proposal very weird.) Information is here seen as an is potentially very important to cognitive objective commodity that actively guides the science which likewise sees information, particle - it is information for the electron and information processing, as its central rather than information for human beings. notions. Bohm himself pointed out that the Fred Dretske had similarly emphasized in way information acts at the quantum level is 1981 that information should be seen as an at least closely analogous to the way infor- objective commodity, although his notion of mation acts in human subjective experience. information is in some key ways different When I see something that means “danger” from Bohm and Hiley’s. (e.g. a snake), the information content acts I should note that Bohm and Hiley’s pro- within the brain, not only via electric action posal about the quantum theoretical active potentials, but also via various neurochemical information is controversial and still mostly processes to prepare the body for an appropri- ignored within the physics community. There ate response (cf. Thagard 2002). are some technical issues with the proposal, Bohm and Hiley’s approach opens up but in my view a major reason is that it goes a whole new way of understanding such so much against the prevalent mechanistic “psycho-somatic” processes. The idea here way of thinking in physics. However, some is that abstract information content is some- leading thinkers do take it seriously, for thing intrinsically active and intrinsically example Quentin Smith (2003). able to cause changes in the more concrete Bohm and Hiley see the existence and underlying physical aspects of the system role of information at the quantum level as in question. This differs in interesting ways an instance of a more general principle of from the more standard, passive notions of active information that prevails in various information typically used in the standard ac- levels of nature.