THE THIRD REALM AND THE FAILURE OF ITS NATURALIZATION IN KARL POPPER’S CONCEPTION OF WORLD

The article discusses Karl Popper’s conception of World 3 as the realm of objective knowledge. The main target is problems of reconciling the thesis that World 3 is autonomous (irreducible) with respect to the physical (World 1) and the mental (World 2) and the thesis that World 3 is a product of human thought. With respect to the problem of the “over crowdedness” of World 3, formulated by L. Cohen, it is suggested that the solution can be looked for in some kind of non-classical (probably, relevance) logic; however, the details are still waiting for elaboration. It is argued that the cultural relativity of knowledge and the non-existence of the demarcation line between the private (mental) and the public modes of existence of an idea constitute graver – and probably insolvable – problems for Popper’s conception. In particular, because there is no plausible way to draw the demarcation, one should consider World 3 either as ontologically derived from a combination of the mental and the physical (the multitude of Worlds 2 in their communication supported and mediated by material information carriers, which belong to World 1 or as a temporal and containing all possible contents of human thought. It is also pointed out that Popper’s attempt at the “biologization” of World 3 and his motto “all life is problem-solving” sit badly with his claims that problems belong to World 3 and that the existence of World 3 is inseparable from the higher functions of human language. The general outcome is that the reconciliation of the view that World 3 is an ontologically irreducible realm with the view that it is human-made is hardly possible. If the irreducibility is admitted, World 3 should be thought of in a more Platonean – or Fregean – way than Popper did admit.