Similarity in several respects between discrete cases. A logical argument by analogy relies upon an inductive inference from the supposition that things are similar is certain known respects to the likelihood that they are also similar in some further unknown respect.

Example: "Jennifer enjoys listening to the music of Beethoven, Mahler, and Bartok. Susan and Harold also like Beethoven, Mahler, and Bartok. Chris enjoys listening to Beethoven and Mahler. Therefore, Chris would probably like the music of Bartok, too."

The degree of reliability achieved by such an argument depends upon the extent and nature of the similarities that hold between the instances in its premises and the new case in its conclusion.

Recommended Reading: G. E. R. Lloyd, Polarity and Analogy: Two Types of Argumentation in Early Greek Thought (Hackett, 1992) and Ralf M. W. Stammberger, On Analogy: An Essay Historical and Systematic (Peter Lang, 1995)

Also see SEP, DPM, Keith J. Holyoak and Paul Thagard, EB, Allison Barnes and Paul Thagard, and Amélie Frost Benedikt.