For discussion, a first post on the subject (apologies if it's too philosophical for some):- ______________ One review of Popper’s contribution to “The Self and Its Brain” [‘TSAIB’] (co-authored with the Nobel laureate J.C. Eccles, though their contributions are individual not joint) said that it’s the closest we have to Popper’s ‘philosophy of mind’. Popper’s way into the subject differs, typically, from many other philosophers. In particular, as Popper says in the first section [marked P1.1], “I am not offering what is sometimes called an ‘ontology’”. Popper’s whole approach is underpinned by his theory of the three worlds or realms – of, roughly, the physical [World 1], mental [World 2] and cultural [World 3]. The distinction drawn between these worlds or realms is an “ontology” of sorts; but what Popper is not attempting to answer is ‘what is it that constitutes something being physical?’, or ‘mental’, or a ‘constituent of World 3’. That is, he is not offering an “ontology” in an essentialist sense, or even in the sense of an introductory text like Colin McGinn’s “The Character of Mind” that appears fixated with questions of ‘what is the mental?’ as opposed to ‘what is the physical?’ It has been an almost life-long aspect of Popper’s approach to decry this kind of philosophising, for a variety of reasons including the absence of ‘ultimate explanations’. In ‘TSAIB’ we see how far we might get without stumbling at the first hurdle of these, to others, seemingly inescapable and yet insurmountable ‘What is?’ questions. It is important to emphasise that Popper’s conception of World 2 includes not just conscious but unconscious mental states; even though, almost of necessity, the focus of his attention on World 2 will be conscious states, and indeed examining these states in their articulated forms as products in World 3 [for example, by examining a World 2 ‘thought’ or ‘mental state’ in a linguistically expressed and therefore World 3 form, including that of a ‘theory’ or explanation], it is clear that most brain activity is not conscious activity or consciously controlled. The ‘conscious mind’ may be the tip of the iceberg in terms of the scope and amount of brain activity. Yet the ‘conscious mind’, and its interaction with World 3 objects [which themselves are the product of the mind], utterly changes what would otherwise be our situation in ways that justify focus on the ‘conscious mind’ [and its products] within any ‘philosophy of mind’. For any adequate of ‘philosophy of mind’ would have to be adequate to account for a work such as ‘TSAIB’ itself. There is an aspect of Popper’s method that invites misunderstanding and should be perhaps mentioned. Popper’s “The Open Society and Its Enemies” has been misread, for example, as being primarily a critique of the political philosophies of Plato, Hegel and Marx; whereas it is a defence of democracy, with many ideas of its own, that is presented by way of criticism of these philosophies. In ‘TSAIB’, likewise, Popper’s “philosophy of mind” is mostly presented by way of criticism of other views, but it would be a similar mistake to think it is simply a set of such critiques. At the same time, Popper takes many of the underlying problems addressed by ‘TSAIB’ to be ‘open’ problems and even insoluble, or at best only partially soluble. This modesty, as to what can be argued for, runs through the book. While Popper elsewhere takes the proponents of ‘inductive logic’ to be on a fool’s errand, the positions he opposes in ‘TSAIB’ are deemed worthy of respect, not just for how they have inspired worthwhile developments [e.g. Popper’s account of “materialism” as a programme of explanation in science, and in the ‘philosophy of mind’] but that they represent schools of thought that may continue to inspire important developments. This is not perhaps so surprising, as Popper is an interactionist and pluralist: that important developments might spring from seeking some ‘materialist’ [or physical-chemical] explanation of the mind, or might spring from seeking some irreducibly psychological or cultural explanation, is more than left open. Both are likely if the truth here involves, as Popper suggests, a complex interaction of entities and phenomena that he divides broadly along the lines of Worlds 1, 2 and 3, with World 2 the only realm that has interaction with both the other realms. Brief outlines of aspects of ‘TSAIB’ with comments:- (1) Popper on so-called 'identity' theories. Identity theories of body and mind, which argue that in some sense a mental event is ‘identical’ to a physical one, raise the question ‘In what sense can we speak of ‘identity’ here?’ What interests Popper is not so much trying to formulate or refute the specifics of an ‘identity’ theory but to understand these as the upshot of a certain kind of underlying metaphysical position. This approach, which eschews surface logic-chopping, is seen also in his wide-ranging survey of possible positions on the body-mind problem, and in his seeing resemblances between positions that might otherwise seem far apart but not when these are considered as part of a deeper metaphysical stance. For example, the kind of radical materialism (that denies there is such a thing as conscious experience a la Quine), and that might seem very far removed from pan-psychism (that says “all matter has an inside aspect which is a soul-like or consciousness-like ‘quality’”), shares, Popper suggests, “a certain simplicity of outlook. The universe is in both cases homogeneous and monistic.” Considering things in this metaphysical sweep, Popper likewise observes, with typical astuteness, that “Epiphenomenalism may be interpreted as a modification of pan-psychism, in which the “pan” element is dropped and the “psychism” is confined to those living things that seem to have a mind” [p.54 of Chapter P3 "Materialism Criticized"]. Donal London