Foundations Of Cognitive Science

Laws of Association

Aristotle considered three different kinds of relationships between a starting image and its successor: similarity, opposition, and (temporal) contiguity: "And this is exactly why we hunt for the successor, starting in our thoughts from the present or from something else, and from something similar, or opposite, or neighboring.  By this means recollection occurs" (Sorabji, 2006, p. 54).  In more modern associationist theories, Aristotle’s laws would be called the law of similarity, the law of contrast, and the law of contiguity or the law of habit.

18th century British empiricists expanded Locke’s approach by exploring and debating possible laws of association.  George Berkeley reiterated Aristotle’s law of contiguity, and extended it to account for associations involving different modes of sensation (Berkeley, 1710).  David Hume proposed three different laws of association: resemblance, contiguity in time or place, and cause or effect (Hume, 1748/1952).  David Hartley, one of the first philosophers to link associative laws to brain function, saw contiguity as the primary source of associations, and ignored Hume’s law of resemblance (Warren, 1921).

 Debates about the laws of association continued into the 19th century.  James Mill only endorsed the law of contiguity, and explicitly denied Hume’s laws of cause or effect and resemblance (Mill, 1829).  Mill’s ideas were challenged and modified by his son, John Stuart Mill.  In his revised version of his father’s book (Mill & Mill, 1869), Mill posited a completely different set of associative laws, which included a reintroduction of Hume’s law of similarity. He also replaced his father’s linear, mechanistic account of complex ideas with a “mental chemistry” that endorsed nonlinear emergence.  This is because in this mental chemistry, when complex ideas were created via association, the resulting whole was more than just the sum of its parts.  Alexander Bain refined the associationism of his lifelong friend John Stuart Mill (Bain, 1855), proposing four different laws of association, and attempting to reduce all intellectual processes to these laws.  Two of these were the familiar Aristotelian laws of contiguity and of similarity.


  1. Bain, A. (1855). The Senses and the Intellect. [S.l.]: Parker.
  2. Berkeley, G. (1710). A Treatise Concerning the Principles of Human Knowledge. Dublin,: Printed by A. Rhames for J. Pepyat.
  3. Hume, D. (1748/1952). An Enquiry Concerning Human Understanding. La Salle, IL: The Open Court Publishing Company.
  4. Mill, J. (1829). Analysis Of The Phenomena Of The Human Mind. London,: Baldwin and Cradock.
  5. Mill, J., & Mill, J. S. (1869). Analysis Of The Phenomena Of The Human Mind (A new edition, with notes illustrative and critical / by Alexander Bain, Andrew Findlater, and George Grote. ed.). London: Longmans, Green, Reader.
  6. Sorabji, R. (2006). Aristotle On Memory (2nd. ed.). Chicago: University of Chicago Press.
  7. Warren, H. C. (1921). A History Of The Association Psychology. New York, NY: Charles Scribner's Sons.

(Added November, 2010)