Analogical Reasoning

64 Pages Posted: 18 Oct 2021 Last revised: 13 Dec 2021

See all articles by Cass R. Sunstein

Cass R. Sunstein

Harvard Law School; Harvard University - Harvard Kennedy School (HKS)

Date Written: October 7, 2021


In law, the process of analogical reasoning appears to work in five simple steps. (1) Some fact pattern A—the “source” case—has certain characteristics; call them x, y, and z. (2) Fact pattern B—the “target” case—has characteristics x, y, and q, or characteristics x, y, z, and q. (3) A is treated a certain way in law. (4) Some principle or rule, announced, created, or discovered in the process of thinking through A, B, and their interrelations, explains why A is treated the way that it is. (5) Because of what it shares in common with A, B should be treated the same way. It is covered by the same principle. It should be clear that the crucial step, and the most difficult, is (4). Often analogical reasoning works through the use of incompletely theorized agreements, making (4) tractable. Some of the disputes about analogical reasoning reflect contests between Burkean and Benthamite conceptions of law.

Keywords: analogical reasoning, rules, case-by-case judgment, Burke, Bentham

JEL Classification: KO, K40

Suggested Citation

Sunstein, Cass R., Analogical Reasoning (October 7, 2021). Harvard Public Law Working Paper No. 21-39, Available at SSRN: or

Cass R. Sunstein (Contact Author)

Harvard Law School ( email )

1575 Massachusetts Ave
Areeda Hall 225
Cambridge, MA 02138
United States
617-496-2291 (Phone)

Harvard University - Harvard Kennedy School (HKS) ( email )

79 John F. Kennedy Street
Cambridge, MA 02138
United States

Do you have negative results from your research you’d like to share?

Paper statistics

Abstract Views
PlumX Metrics