One of the main problems for an attempted science of consciousness is that the truth makers of a judgement about consciousness are apparently only privately available. For example, a pain can only be felt by one person. Epistemically, for each phenomenal token, one and only one epistemic subject has direct epistemic access (e.g. can attend) to this token, while other epistemic subject may only infer from correlates. For a judgement like „Pains are unpleasant.“, any subject can access only one different subclass of truthmaking tokens, namely only her own pains. That is, the sets of accessible truthmakers are mutually exclusive: Nobody else can feel this specific pain that I feel and judge about by acquaintance.

Science, however, is reliant on intersubjective methods of critique. It is obvious that we cannot give up this position: Any science, may it be biology, physics, sociology, economics or history of art must have its evidence or its instances of refutation in principle available to all members of the scientific community. If we were to give up this basic axiom, we would give up the basis of mistake minimisation by the community, and revelations might become scientific method.

A science of consciousness must deal with this basic tension between the intersubjectivity of scientific methodology and the subjectivity and privateness of its subject matter, especially when it comes to introspective judgments about these phenomena. This has been acknowledged by philosopher Ned Block (2007) by stating Epistemic Correlationism: when we want to verify in experimental setting whether a specific phenomenal state is present to the experimental subject, we have to correlate it with a judgement made by the subject, expressed by report, button pressing or metacognitive access.

There are three plausible options: (1) Introspection, our immediate access to phenomena, is reliable. Then, we could trust in first-person reports. This is doubtful. (2) Introspection is replaceable. Then, we would not need to rely on reports to inquire consciousness. I pose an argument against this, at least for research in Neural Correlates of Consciousness. (3) Introspective judgements are correctable. Then, even if the referrents of these judgements are not intersubjectively accessible, at least the correctness of the reports can be evaluated.

The main aim of the project is to elucidate the argumentative strategies to reject a phenomenological claim, following the strategy in (3). This may reveal the limits of a science of consciousness: If such arguments exist, they might be limited to a subclass of phenomenal ontology. If they are, then this subclass may be the sole target for scientific inquiry.

I defend that such arguments exist, but that they are limited to the modalities and generality of phenomenal metaphysics, that is: claims about what is necessary to experience. We are also limited to structural knowledge – knowledge of the relations that hold between different experiences. To distinguish between different kinds of arguments, I rely on the tools provided by recent work in possible world semantics, e.g. by Robert Stalnaker (2007). In conclusion, I hold that a science of consciousness is possible and hope to sketch its basic argumentative foundations.