Radical Scepticism, How-Possible Questions and Modest Transcendental Arguments

Abstract

According to radical scepticism, knowledge of the external world is impossible. Transcendental arguments are supposed to be anti-sceptical, but can they provide a satisfying response to radical scepticism? Especially, when radical scepticism is cast as posing a how-possible question, there is a concern that transcendental arguments are neither sufficient nor necessary for answering such question. In light of this worry, I argue that we can take a modest transcendental argument as a stepping stone for a diagnostic anti-sceptical proposal, and I use a Wittgensteinian modest transcendental argument to illustrate my point.

Keywords:

• Sceptical paradox
• Wittgenstein
• hinge commitments
• how-possible questions
• diagnosis

Notes

1. For proponents of regarding radical scepticism qua paradox, for example, see Stroud (1984), DeRose (1995), Wright (2008) and Pritchard (2015).

2. Following Pritchard (2005, 38), we can formulate the closure principle slightly differently: (CK) For all S, p, q, if S knows that p, and S can competently deduce q from p, then S is in a position to know that q.

3. Here ‘epistemic standards’ do not refer to ordinary epistemic standards according to which there is a relatively low requirement on knowledge evaluation. Rather, epistemic standards involve epistemic principles and concepts that are intuitively endorsed by us, such as the closure principle, and the idea that perceptual knowledge requires perceptual discrimination (hence one cannot distinguish subjectively indistinguishable sceptical scenarios from everyday scenarios).

4. For similar distinctions, see Cassam (2007, 2) and Pritchard (2015, 16).

5. For this understanding, see Stern 1999; Davidson 1999.

6. Roughly put, Stroud argues that ambitious transcendental arguments are either superfluous in that they must trade on verificationism or idealism to bridge the gap between a psychological fact and a non-psychological fact, and therefore the anti-sceptical work is done primarily by verificationism or idealism; or, given that they don’t establish a non-psychological conclusion, they are disappointing because they fail to answer the sceptic.

7. A transcendentalist is a proponent of a transcendental argument. For prominent proponents of modest transcendental arguments, see Stroud 1999; Stern 2007.

8. One crucial objection to modest transcendental arguments is whether we are epistemically justified in believing the conclusions of those arguments: see e.g. Brueckner 1986; Vahid 2011.

9. He doesn’t distinguish two kinds of transcendental arguments, so I think he intends to apply his objection to both kinds.

10. The term ‘obstacle-dependent’ is used by Cassam (2007, 3).

11. There is a shared view that these two arguments are the most important sceptical arguments. For more discussion, see Brueckner 1994; Pritchard 2005; Wang 2014.

12. See a similar point in Pritchard 2009.

13. Cassam (2007, 51) attributes the view that by means of transcendental arguments is the best way to answer how-possible question to Hatfield (1990) and Collins (1999).

14. Note that Cassam (2007, 52) maintains that transcendental arguments might have a legitimate role in epistemology, but not in answering how-possible questions.

15. Also, see earlier discussions of methodological indispensability in Stern (2000, 81) and Ranalli (2013, 140).

16. P has methodological necessity in the sense that P is methodologically necessary for our epistemic practice.

17. Here sceptics would be limited to those who share the premise that we have beliefs. Note that in the sceptical paradox, the sceptic grants that we have beliefs. What she denies is that our beliefs constitute knowledge.

18. This inference includes the assumption that belief is a necessary condition of knowledge.