Topics Logic

Question What is analogy? I read Wikipedia's article on the subject and I found it a bit vague or something (for my poor brain, at least...). Is analogy the same as metaphor? Is analogical thinking non-scientific? As far as I see it, politicians are always drawing on analogies. Isn't that just rhetoric? I searched your site and I found the word "analogy" several times, but its use never seemed decisive to answer the questions.

Accepted:
November 11, 2005

Comments

The simplest form of inductive reasoning follows the principle 'more of the same': if we have seen a pattern and have no special reason to think it will change, then we tend to predict that it will stay the same. We have noticed in the past that fire has been hot, so we predict it will be hot in the future too. This form of induction, basic to ordinary life and science alike, seems to operate on a principle of analogy: we are taking it that future events will be analogous to past ones. (Then along comes David Hume, with a devastating argument that we have no non-circular way of showing that the unobserved will be analgous to the observed.)

Thomas Kuhn, in his important book The Structure of Scientific Revolutions, brings out another way that analogy is central to science. When scientists choose which new problems to tackle, they are often guided by principles of analogy. They choose problems that seem similar to problems they have already solved, and they apply techniques analagous to those that worked on the old problems.