9 ideas
6950 | You can be rational with undetected or minor inconsistencies [Harman] |
Full Idea: Rationality doesn't require consistency, because you can be rational despite undetected inconsistencies in beliefs, and it isn't always rational to respond to a discovery of inconsistency by dropping everything in favour of eliminating that inconsistency. | |
From: Gilbert Harman (Rationality [1995], 1.2) | |
A reaction: This strikes me as being correct, and is (I am beginning to realise) a vital contribution made to our understanding by pragmatism. European thinking has been too keen on logic as the model of good reasoning. |
6954 | A coherent conceptual scheme contains best explanations of most of your beliefs [Harman] |
Full Idea: A set of unrelated beliefs seems less coherent than a tightly organized conceptual scheme that contains explanatory principles that make sense of most of your beliefs; this is why inference to the best explanation is an attractive pattern of inference. | |
From: Gilbert Harman (Rationality [1995], 1.5.2) | |
A reaction: I find this a very appealing proposal. The central aim of rational thought seems to me to be best explanation, and I increasingly think that most of my beliefs rest on their apparent coherence, rather than their foundations. |
6955 | Enumerative induction is inference to the best explanation [Harman] |
Full Idea: We might think of enumerative induction as inference to the best explanation, taking the generalization to explain its instances. | |
From: Gilbert Harman (Rationality [1995], 1.5.2) | |
A reaction: This is a helpful connection. The best explanation of these swans being white is that all swans are white; it ceased to be the best explanation when black swans turned up. In the ultimate case, a law of nature is the explanation. |
6952 | Induction is 'defeasible', since additional information can invalidate it [Harman] |
Full Idea: It is sometimes said that inductive reasoning is 'defeasible', meaning that considerations that support a given conclusion can be defeated by additional information. | |
From: Gilbert Harman (Rationality [1995], 1.4.5) | |
A reaction: True. The point is that being defeasible does not prevent such thinking from being rational. The rational part of it is to acknowledge that your conclusion is defeasible. |
6953 | All reasoning is inductive, and deduction only concerns implication [Harman] |
Full Idea: Deductive logic is concerned with deductive implication, not deductive reasoning; all reasoning is inductive | |
From: Gilbert Harman (Rationality [1995], 1.4.5) | |
A reaction: This may be an attempt to stipulate how the word 'reasoning' should be used in future. It is, though, a bold and interesting claim, given the reputation of induction (since Hume) of being a totally irrational process. |
14367 | An explanation is a causal graph [Woodward,J, by Strevens] |
Full Idea: On Woodward's manipulationist view, an explanation would take the form of a causal graph. | |
From: report of James Woodward (Making Things Happen [2003]) by Michael Strevens - No Understanding without Explanation 1 | |
A reaction: The idea is that causation is all to do with how nature responds when you try to manipulate it. I'm certainly in favour of tying explanation closely to causation. |
6951 | Ordinary rationality is conservative, starting from where your beliefs currently are [Harman] |
Full Idea: Ordinary rationality is generally conservative, in the sense that you start from where you are, with your present beliefs and intentions. | |
From: Gilbert Harman (Rationality [1995], 1.3) | |
A reaction: This stands opposed to the Cartesian or philosophers' rationality, which requires that (where possible) everything be proved from scratch. Harman seems right, that the normal onus of proof is on changing beliefs, rather proving you should retain them. |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |