| 3033 | Induction moves from some truths to similar ones, by contraries or consequents [Diog. Laertius] |
| Full Idea: Induction is an argument which by means of some admitted truths establishes naturally other truths which resemble them; there are two kinds, one proceeding from contraries, the other from consequents. | |
| From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 3.1.23) |
| 6350 | Premises can support an argument without entailing it [Pollock/Cruz on Hume] |
| Full Idea: Contrary to what Hume supposed, it must be possible for the premises of an argument to support a conclusion without logically entailing it. | |
| From: comment on David Hume (Enquiry Conc Human Understanding [1748]) by J Pollock / J Cruz - Contemporary theories of Knowledge (2nd) §1.2 | |
| A reaction: This seems to me an extremely important point, made with nice clarity. It is why people who are good at logic are not necessarily good at philosophy. The latter is about thinking rationally, not following the laws of deduction. |
| 3598 | Hume just shows induction isn't deduction [Williams,M on Hume] |
| Full Idea: All that Hume has really shown with his argument is that induction is not deduction. | |
| From: comment on David Hume (Enquiry Conc Human Understanding [1748], IV.II.29) by Michael Williams - Problems of Knowledge Ch.18 |
| 13055 | Good induction needs 'total evidence' - the absence at the time of any undermining evidence [Salmon] |
| Full Idea: Inductive logicians have a 'requirement of total evidence': induction is strong if 1) it has true premises, 2) it has correct inductive form, and 3) no additional evidence that would change the degree of support is available at the time. | |
| From: Wesley Salmon (Four Decades of Scientific Explanation [1989], 2.4.2) | |
| A reaction: The evidence might be very close at hand, but not quite 'available' to the person doing the induction. |
| 3860 | Science cannot be shown to be rational if induction is rejected [Newton-Smith on Popper] |
| Full Idea: If Popper follows Hume in abandoning induction, there is no way in which he can justify the claims that there is growth of scientific knowledge and that science is a rational activity. | |
| From: comment on Karl Popper (The Logic of Scientific Discovery [1934]) by W.H. Newton-Smith - The Rationality of Science III.3 |
| 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. |
| 3251 | Observed regularities are only predictable if we assume hidden necessity [Nagel] |
| Full Idea: Observed regularities provide reason to believe that they will be repeated only to the extent that they provide evidence of hidden necessary connections, which hold timelessly. | |
| From: Thomas Nagel (The View from Nowhere [1986], V.5) |
| 16800 | An inductive inference is underdetermined, by definition [Lipton] |
| Full Idea: If an inference is inductive, then by definition it is underdetermined by the evidence and the rules of deduction. | |
| From: Peter Lipton (Inference to the Best Explanation (2nd) [2004], 01 'Underd') |
| 16858 | We can argue to support our beliefs, so induction will support induction, for believers in induction [Lipton] |
| Full Idea: There is nothing illegitimate about giving arguments for beliefs one already holds. …So inductive justification of induction, while impotent against the skeptic, is legitimate for those who already rely on induction. | |
| From: Peter Lipton (Inference to the Best Explanation (2nd) [2004], 11 'Circularity') | |
| A reaction: Not so fast! The first sentence is generally right, but if the 'beliefs one already holds' are beliefs about methods of argument, that is a different case. Compare 'this book is the word of God, because it says so in the book'. Can logic prove logic? |
| 4811 | Induction (unlike deduction) is non-monotonic - it can be invalidated by new premises [Psillos] |
| Full Idea: Unlike deductive arguments, induction is non-monotonic - that is, it can be invalidated by the addition of new premises. | |
| From: Stathis Psillos (Causation and Explanation [2002], §9.2.1) | |
| A reaction: This is a fancy way of stating the obvious, which is that induction is not a type of deduction. Hume is sometimes accused of this false assumption. Presumably induction is rational, even if it is not actually logical. |
| 4583 | How can an argument be good induction, but poor deduction? [Baggini /Fosl] |
| Full Idea: The problem of induction is the problem of how an argument can be good reasoning as induction but poor reasoning as deduction. | |
| From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.03) | |
| A reaction: Nicely put, and a good defence of Hume against the charge that he has just muddled induction and deduction. All reasoning, we insist, should be consistent, or it isn't reasoning. |
| 14914 | Inductive defences of induction may be rule-circular, but not viciously premise-circular [Ladyman/Ross] |
| Full Idea: The inductive defence of induction may be circular but not viciously so, because it is rule circular (defending the rule being used) but not premise circular (where the conclusion is in one of the premises). | |
| From: J Ladyman / D Ross (Every Thing Must Go [2007], 2.1.2) | |
| A reaction: [They cite Braithwaite 1953 and Carnap 1952 for this] This strikes me as clutching at straws, when the whole procedure of induction is inescapably precarious. It is simply all we have available. |