Science is not in itself scientistic. Only the use made of science can be scientistic. Scientistic dogmatism comes in when your only model of cognition is science and everything else is made to conform to that. Pushed to its logcial consequences in speculative projects such as cognitive materialism, scientism is both dogmatic and self-refuting. It bases itself on an extrapolation of selected scientific theories and results, and not only concludes to our absence of freedom but also proves our cognitive insufficiency, without noticing that it proves the cognitive insufficiency of its own evidence. This whole problematic of cognitive illusion was already to be found in Pyrrho and Sextus Empiricus, so at this level there is no need to refer to modern science.
The reference to science comes up in order to give a stable dogmatic foundation to an unstable mass of heuristic observations and conjectures concerning the determination of our cognitive functions, i.e. it occurs when the scientistic materialist is making use of science metaphysically to say boo! to other metaphysicians. When they reply “Boo yourself!”, the scientistic materialist is perplexed and declares that they are not answering the question. But “Boo!” is not a question, even if it is expressed in a sentence that is grammatically in the interrogative mood. Johnston does exactly the same thing as the cognitive materialist, he makes speculative leaps. The difference is that he acknowledges that this is so, and makes room for it in his own theorisation of what he is doing.
There is not the slightest scientific procedure in what either are doing, it’s all metaphysical selection and use of a partial set of scientific results. Neither has “science” on its side, both transcendental materialism and scientistic materialism make a metaphysical selection and extrapolation, the only difference is that scientistic materialism if followed through shows that science as cognition is impossible. Both make use of a selection from science that is partial, one-sided, frozen, and pre-oriented to the conclusion they have already opted for metaphysicall. They are both doing metaphysics not science, which is fine, but then scientistic materialism has no criterion of demarcation between itself and Johnston’s speculative materialism.
However, Johnston does have such a criterion of demarcation. He formulates my objection in his own terms by saying that Nature is “a detotalized, disunified non-One/not-All of distinct, heterogeneous levels and layers of beings”. Scientistic materialism is in effect totalizing and homogenizing, its Nature is unified by its own grounding metaphysical speculation, despite its claim to share in the objective empirical status of the scientific research that it selects and extrapolates. Scientistic materialism is a plucked metaphysical duck to which has been stuck real scientific swan feathers to make us think it is a scientific swan, but its quack betrays it.