The whole direction of empiricism for at least a hundred years has been to argue that speculation is an essential, ineliminable, and positive ingredient of our knowledge -being both heuristically useful and compositionally fecund. Were Russell, Carnap, Quine, and Popper against “speculation”? Far from it, they argued for its necessity and for its usefulness. And this is just taking examples from the empiricist camp. Richard Rorty came out in favour of the creation of new speculative vocabularies. Feyerabend from his early beginnings to his last writings was in favour of both speculation and realism. This is what attracted him to Popper in the first place, and what separated him later. Feyerabend’s major critique of Popper was that he put too many constraints on the use of speculation, and that therefore his realism was not thoroughgoing, containing dogmatic untestable elements hidden in the presuppositions of his methodological assumptions.
Contrary to a mistaken image promulgated regularly by partisan commentators, there has been no generalised abandon of speculation in anglophone philosophy in the name of the dogmas of a flat empiricism. Rather there has been a continuous critique of certain types of empty specualtion. I am not talking about narcissistic fights or diplomatic tolerances, I am advocating making our speculation testable, by all means possible. This was behind Feyerabend’s realist defence of speculation:
“As opposed to positivism, a realistic position does not admit any dogmatic and incorrigible statement into the field of knowledge. Hence, also, our knowledge of what is observed is not regarded as unalterable and this in spite of the fact that it may have a counterpart in the phenomena themselves. This means that at times interpretations will have to be considered which do not ‘fit’ the phenomena and which clash with what is immediately
given. Interpretations of this kind could not possibly emerge from close attention to the ‘facts’. It follows that we need a non-observational source for interpretations. Such a source is provided by (metaphysical) speculation which is thus shown to play an important role within realism. However, the results of such speculation must be made testable, and having been transformed in this way they must be interpreted as descriptive of general features of the world (otherwise we are thrown back upon the old account of what is observed)”. (Feyerabend, “Attempt at a realistic experience of experience”, originally published in 1958).
All this is in the context of speculation as it occurs within the sciences. But one can also pose the question at a higher level of abstraction, that of the value and interest of philosophical speculation in general. His later meditations on Being (especially in CONQUEST OF ABUNDANCE) would suggest however that both speculation within science and external speculative extrapolations of scientific results cannot exhaust the meaning of Being and cannot be imposed on full-fledged traditions that interpret and experience things otherwise.
One such external extrapolation is eliminativism, a speculation that often tries to present itself as the only possible conclusion from the results of modern science. I myself am not an eliminativist, although I think that eliminativism is a line of thinking that is worth pursuing, and thus I defend it against a certain type of non-empirical objection. Eliminativism sharpens the debate and produces interesting hypotheses, but so also do hypotheses of the unconscious that make no reference to material inscription and indeed relativise its meaning and importance. Perhaps neuronal unconscious may ultimately replace the specific hypothesis of the Freudian unconscious, although this is a mere programmatic speculation for the moment. But I don’t see the hypothesis of the unconscious in its most general form (as in Lacan, Jung, Deleuze and Guattari, Stiegler) give up the ghost so easily. Eliminativism, from this point of view, is just one cognitive style amongst many. That said I think it is heuristically useful to pursue the eliminativist programme as an aid to thinking and research.
Eliminativism in Badiou’s terms arises from a recurrent danger in the history of speculative thought: the suture of philosophy to one of its conditions. Eliminativism arises from the suture of philosophy to the condition of science, itself identified with a narrow selection of its purported content. Whence it’s contradictory self-image of of both not being speculation at all, and being a much more plausible hypothesis than its speculative rivals.