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Ideas of Thomas Grundmann, by Text

[German, fl. 2011, Professor at Cologne University.]

2011 Defeasibility Theory
'Defeater-Defs' p.162 Can a defeater itself be defeated?
     Full Idea: Can the original justification of a belief be regained through a successful defeat of a defeater?
     From: Thomas Grundmann (Defeasibility Theory [2011], 'Defeater-Defs')
     A reaction: [Jäger 2005 addresses this] I would have thought the answer is yes. I aspire to coherent justifications, so I don't see justifications as a chain of defeat and counter-defeat, but as collective groups of support and challenge.
'Defeaters' p.160 Simple reliabilism can't cope with defeaters of reliably produced beliefs
     Full Idea: An unmodified reliabilism does not accommodate defeaters, and surely there can be defeaters against reliably produced beliefs?
     From: Thomas Grundmann (Defeasibility Theory [2011], 'Defeaters')
     A reaction: [He cites Bonjour 1980] Reliabilism has plenty of problems anyway, since a generally reliable process can obviously occasionally produce a bad result. 20:20 vision is not perfect vision. Internalist seem to like defeaters.
'How' p.158 You can 'rebut' previous beliefs, 'undercut' the power of evidence, or 'reason-defeat' the truth
     Full Idea: There are 'rebutting' defeaters against the truth of a previously justified belief, 'undercutting' defeaters against the power of the evidence, and 'reason-defeating' defeaters against the truth of the reason for the belief.
     From: Thomas Grundmann (Defeasibility Theory [2011], 'How')
     A reaction: That is (I think) that you can defeat the background, the likelihood, or the truth. He cites Pollock 1986, and implies that these are standard distinctions about defeaters.
'Significance' p.163 Indefeasibility does not imply infallibility
     Full Idea: Infallibility does not follow from indefeasibility.
     From: Thomas Grundmann (Defeasibility Theory [2011], 'Significance')
     A reaction: If very little evidence exists then this could clearly be the case. It is especially true of historical and archaeological evidence.
'Significance' p.164 'Moderate' foundationalism has basic justification which is defeasible
     Full Idea: Theories that combine basic justification with the defeasibility of this justification are referred to as 'moderate' foundationalism.
     From: Thomas Grundmann (Defeasibility Theory [2011], 'Significance')
     A reaction: I could be more sympathetic to this sort of foundationalism. But it begins to sound more like Neurath's boat (see Quine) than like Descartes' metaphor of building foundations.
'What' p.157 Defeasibility theory needs to exclude defeaters which are true but misleading
     Full Idea: Advocates of the defeasibility theory have tried to exclude true pieces of information that are misleading defeaters.
     From: Thomas Grundmann (Defeasibility Theory [2011], 'What')
     A reaction: He gives as an example the genuine news of a claim that the suspect has a twin.
'What' p.157 Knowledge requires that there are no facts which would defeat its justification
     Full Idea: The 'defeasibility theory' of knowledge claims that knowledge is only present if there are no facts that - if they were known - would be genuine defeaters of the relevant justification.
     From: Thomas Grundmann (Defeasibility Theory [2011], 'What')
     A reaction: Something not right here. A genuine defeater would ensure the proposition was false, so it would simply fail the truth test. So we need a 'defeater' for a truth, which must therefore by definition be misleading. Many qualifications have to be invoked.