Online research in philosophy

A defense of Frank Jackson's knowledge argument from an objection raised by Michael Tye (1986, 1989), according to which Mary acquires no new factual knowledge when she first sees red but, instead, merely comes to know old facts (that she already knew) in a new way.

The definitive statement of the Knowledge Argument was formulated by Frank Jackson, in a paper entitled “Epiphenomenal Qualia” that appeared in The Philosophical Quarterly in 1982. Arguments in the same spirit had appeared earlier (Broad 1925, Robinson 1982), but Jackson’s argument is most often compared with Thomas Nagel’s argument in “What is it Like to be a Bat?” (1974). Jackson, however, takes pains to distinguish his argument from Nagel’s. This entry will follow standard practice in focusing on Jackson’s argument, though I will also describe the main points of alleged similarity and dissimilarity between these two arguments.

The knowledge argument aims to refute physicalism, the view that the world is entirely physical. The argument first establishes the existence of facts (or truths or information) about consciousness that are not a priori deducible from the complete physical truth, and then infers the falsity of physicalism from this lack of deducibility. Frank Jackson (1982, 1986) gave the argument its classic formulation. But now he rejects the argument (Jackson 1998b, 2003, chapter 3 of this volume). On his view, it relies on a false conception of sensory experience, which should be replaced with representationalism (also known as intentionalism), the view that phenomenal states are just representational states. And he argues that mental representation is physically explicable.

Frank Jackson has abandoned his famous knowledge argument, and has explained why in a brief "Postscript on Qualia" (1998). This explanation consists of a direct argument, and an attempt to explain away the intuition that lies at the heart of the knowledge argument. The direct argument is clarified and found to be subtly question-begging. The attempt to explain away the key intuition is reviewed and found to be inadequate. False memory traces, which Jackson mentions at the beginning of the direct argument, are discussed and found not to materially affect the force of the knowledge argument.

Frank Jackson argued, in an astronomically frequently cited paper on 'Epiphenomenal qualia'[Jackson 1982 that materialism must be mistaken. His argument is called the knowledge argument. Over the years since he published that paper, he gradually came to the conviction that the conclusion of the knowledge argument must be mistaken. Yet he long remained totally unconvinced by any of the very numerous published attempts to explain where his knowledge argument had gone astray. Eventually, Jackson did publish a diagnosis of the reasons why, he now thinks, his knowledge argument against materialism fails to prove the falsity of materialism [Jackson 2005. He argues that you can block the knowledge argument against materialism - but only if you tie yourself to a dubious doctrine called representationalism. We argue that the knowledge argument fails as a refutation of either representational or nonrepresentational materialism. It does, however, furnish both materialists and dualists with a successful argument for the existence of distinctively first-person modes of acquaintance with mental states. Jackson's argument does not refute materialism: but it does bring to the surface significant features of thought and experience, which many dualists have sensed, and most materialists have missed.

Frank Jackson's knowledge argument against physicalism has caused an extensive debate. In this paper, I sketch and examine a new argument against Jackson's view, an argument which appears to retain more of physicalism than other replies to Jackson. this argument draws strength from a causal theory of knowledge, and hold that there is no knowledge of epiphenomenal qualia, hence that Jackson's main conclusions from the thought experiment are incorrect. There are still problems with this argument, however, so the question remains how much of the mental that can be accounted for in physicalist terms.

I defend Frank Jackson's knowledge argument against physicalism in the philosophy of mind from a criticism that has been advanced by Laurence Nemirow and David Lewis. According to their criticism, what Mary lacked when she was in her black and white room was a set of abilities; she did not know how to recognize or imagine certain types of experience from a first-person perspective. Her subsequent discovery of what it is like to experience redness amounts to no more than her acquisition of these abilities. The physicalist can admit this, since it does not commit one to the view that there are any facts of which Mary was ignorant (in spite of her exhaustive knowledge of truths about the physical world). I argue against this view, on the grounds that the knowledge of what an experience is like cannot be equated with the possession of any set of abilities.

Frank Jackson first presented the Knowledge Argument (henceforth KA) in "Epiphenomenal Qualia" 1982). The KA is an argument against physicalism, the doctrine that (very roughly put) everything is physical. The general thrust of the KA is that physicalism errs by misconstruing or denying the existence of the subjective features of experience. Physicalists have given numerous responses, and the debate continues about whether the KA ultimately succeeds in refuting any or all forms of physicalism. Jackson himself has recently.

Yujin Nagasawa has recently defended Frank Jackson’s knowledge argument from the “inconsistency objection.” The objection claims that the premises of the knowledge argument are inconsistent with qualia epiphenomenalism. Nagasawa defends Jackson by showing that the objection mistakenly assumes a causal theory of phenomenal knowledge. I argue that although this defense might succeed against two versions of the inconsistency objection, mine is unaffected by Nagasawa’s argument, in which case the inconsistency in the knowledge argument remains.