17 ideas
| 8886 | Being a true justified belief is not a sufficient condition for knowledge [Gettier] |
| Full Idea: The claim that someone knows a proposition if it is true, it is believed, and the person is justified in their belief is false, in that the conditions do not state a sufficient condition for the claim. | |
| From: Edmund L. Gettier (Is Justified True Belief Knowledge? [1963], p.145) | |
| A reaction: This is the beginning of the famous Gettier Problem, which has motivated most epistemology for the last forty years. Gettier implies that justification is necessary, even if it is not sufficient. He gives two counterexamples. |
| 19682 | Internalists are much more interested in evidence than externalists are [McGrew] |
| Full Idea: The notion of evidence generally plays a much more significant role in internalist epistemologies than it does in various forms of externalism. | |
| From: Timothy McGrew (Evidence [2011], 'Prop..') | |
| A reaction: I'm guessing that this is because evidence needs a certain amount of interpretation, whereas raw facts (which externalists seem to rely on) may never even enter a mind. |
| 19684 | Does spotting a new possibility count as evidence? [McGrew] |
| Full Idea: Does the sudden realization of a heretofore unrecognized possibility count as evidence? | |
| From: Timothy McGrew (Evidence [2011], 'Evid..') | |
| A reaction: [Nice use of 'heretofore'! Why say 'previously' when you can keep these wonderful old English words alive?] This means that we can imagine new evidence ('maybe the murderer was a snake'!). Wrong. The evidence is what suggests the possibility. |
| 19687 | Absence of evidence proves nothing, and weird claims need special evidence [McGrew] |
| Full Idea: Two well know slogans (popularised by Carl Sagan) are 'absence of evidence is not evidence of absence', ...and 'extraordinary claims require extraordinary evidence'. | |
| From: Timothy McGrew (Evidence [2011], 'Absence') | |
| A reaction: [Sagan was a popular science writer and broadcaster] The second one is something like Hume's argument against miracles. The old problem of the 'missing link' for human evolution embodied the first idea. |
| 19688 | Every event is highly unlikely (in detail), but may be perfectly plausible [McGrew] |
| Full Idea: At a certain level of detail, almost any claim is unprecedented. How likely is 'Matilda won at Scrabble on Thursday with a score of 438 while drinking mint tea'? But there is nothing particularly unbelievable about the claim. | |
| From: Timothy McGrew (Evidence [2011], 'Extraordinary') | |
| A reaction: A striking idea, which rules out the simplistic idea that we can just assess evidence by its isolated likelihood. Context is crucial. How good is 438? What if she smoked opium? What if there is no Scrabble set on her island? |
| 19686 | Criminal law needs two separate witnesses, but historians will accept one witness [McGrew] |
| Full Idea: An ancient rule in law is that a criminal conviction needs evidence of two independent witnesses, but in history it is assumed that a document deserves the benefit of the doubt if it cannot be independently verified. | |
| From: Timothy McGrew (Evidence [2011], 'Interp..') | |
| A reaction: [compressed; McGrew's full account qualifies it a bit] A nice observation. One might even be suspicious of the two 'independent' witnesses, if there were lots of other reasons to doubt someon's guilt. A single weird document is also dubious. |
| 19680 | Maybe all evidence consists of beliefs, rather than of facts [McGrew] |
| Full Idea: Some philosophers have been attracted to the view that, strictly speaking, what counts as evidence is not a set of physical objects or even experiences, but rather a set of believed propositions. | |
| From: Timothy McGrew (Evidence [2011], 'Prop..') | |
| A reaction: This may be right. However, as always, I think animals are a key test. Do animals respond to evidence? Even if they did, they might need to 'make sense' of what they experienced, and even formulate a non-linguistic proposition. |
| 19681 | If all evidence is propositional, what is the evidence for the proposition? Do we face a regress? [McGrew] |
| Full Idea: Taking evidence as propositional may trade one problem for another. If the bloodstain isn't evidence, but 'this is a bloodstain' is evidence, then what serves as evidence for the belief about the bloodstain? Is there an infinite regress? | |
| From: Timothy McGrew (Evidence [2011], 'Prop..') | |
| A reaction: [compressed] I quite like evidence being propositional, but then find this. I'll retreat to my beloved coherence. I do not endorse Sellars's 'only a belief can justify a belief', because raw experience has to be part of what is coherent. |
| 19689 | Several unreliable witnesses can give good support, if they all say the same thing [McGrew] |
| Full Idea: The testimony of a number of independent witnesses, none of them particularly reliable, who give substantially the same account of some event, may provide a strong argument in its favor. | |
| From: Timothy McGrew (Evidence [2011], 'Testimonial') | |
| A reaction: A striking point. It obviously works well for panicking people in a crowd during an incident. Does it also apply to independent scientists who are known to cheat? They may not collaborate, but may all want the same result. |
| 17771 | How we evaluate evidence depends on our background beliefs [Bayne] |
| Full Idea: A claim that might be very plausible given one set of background beliefs might be highly implausible when evaluated in the light of a different set of background beliefs. | |
| From: Tim Bayne (Thought: a very short introduction [2013], Ch.7) |
| 17770 | Clifford's dictum seems to block our beliefs in morality, politics and philosophy [Bayne] |
| Full Idea: Endorsing Clifford's dictum threatens to undermine our right to hold many of our most cherished beliefs about morality, politics, and philosophy, for these are domains in which it is notoriously difficult to secure consensus. | |
| From: Tim Bayne (Thought: a very short introduction [2013], Ch.7) | |
| A reaction: I would say that those beliefs are amenable to evidence, but the evidence is often highly generalised, which is what makes those subjects notoriously difficult. The existence of a convention is a sort of evidence. |
| 19683 | Narrow evidentialism relies wholly on propositions; the wider form includes other items [McGrew] |
| Full Idea: Evidentialism comes in both narrow and wide forms depending on whether evidence is taken to consist only of propositions or of a wider range of items. | |
| From: Timothy McGrew (Evidence [2011], 'Evid..') | |
| A reaction: [He cites Conee and Feldman for the wide view, which is not restricted to beliefs] You can hardly rely on occurrent beliefs as evidence, so we often have good knowledge with forgotten justification. But such knowledge has been 'weakened'. |
| 19685 | Falsificationism would be naive if even a slight discrepancy in evidence killed a theory [McGrew] |
| Full Idea: Data do not quite speak for themselves, which speaks against a naive form of falsificationism according to which even the slightest mismatch between theory and evidence suffices to overturn a theory. | |
| From: Timothy McGrew (Evidence [2011], 'Interp..') | |
| A reaction: [He cites Robert Boyle wisely ignoring some data to get a good fit for his graph] |
| 17766 | Physicalism correlates brain and mind, explains causation by thought, and makes nature continuous [Bayne] |
| Full Idea: The motivations for physicalism about the mind are that it accounts for correlations between states of the brain and states of thought, ...that it accounts for the causal role of thoughts, ...and that it does justice to the continuity of nature. | |
| From: Tim Bayne (Thought: a very short introduction [2013], Ch.2) | |
| A reaction: [summary] That is a pretty good summary of why I am a physicalist about the mind. I take all other theories to be dead footnotes in the history of thought - unless someone can produce a really good new argument. Which they can't. |
| 17768 | Perception reveals what animals think, but humans can disengage thought from perception [Bayne] |
| Full Idea: One striking feature of human thought involves our ability to disengage the focus of thought from that of our perceptual attention. ...To get a fix on what an animal is thinking about, one need only determine the object of its perceptual attention. | |
| From: Tim Bayne (Thought: a very short introduction [2013], Ch.4) | |
| A reaction: What happens when an animal closes its eyes, or stirs violently during sleep? I take the hallmark of human thought to be its multi-level character, and this offers nice evidence for that view. Doing philosophy while driving a car is very revealing. |
| 17769 | Some people centre space on themselves; others centre space on the earth [Bayne] |
| Full Idea: Egocentric conceptions of space employ a frame of reference that is focused on oneself; ...geocentric conceptions of space, by contrast, employ a frame of reference that is centred on the earth. | |
| From: Tim Bayne (Thought: a very short introduction [2013], Ch.5) | |
| A reaction: Famously, Europeans nearly always employ the egocentric conception, but many other cultures are geocentric. Thus the salt cellar is either 'to my left' or 'to the west'. In the latter view, everyone always knows their orientation (even indoors?). |
| 17767 | The alternative to a language of thought is map-like or diagram-like thought [Bayne] |
| Full Idea: One could think that the structure of thought has more in common with that of maps or diagrams, and is not particularly language-like. | |
| From: Tim Bayne (Thought: a very short introduction [2013], Ch.2) | |
| A reaction: It seems unwise to be ensnared by analogies on this one, since the phenomenon is buried deep. You can no more infer what goes on underneath than you can infer electrons from looking at trees? |