“John Locke developed associationist psychology in "An Essay Concerning Human Understanding" (1689), which was later extended by David Hartley in "Observations on Man" (1749).”

First published in two volumes in 1749, Observations on Man is notable for being based on the doctrine of the **association of ideas**. It greatly influenced scientists, theologians, social reformers and poets. In Volume 1, Hartley utilises Newtonian science in his observations. He presents a theory of 'vibrations', explaining how the elements of the nerves and brain interact as a result of stimulation, creating '**associations**' and emotions.

Locke's Essay Concerning Human Understanding (1689) presents a comprehensive empiricist theory of mind based on sensation and reflection as sources of ideas. Locke distinguishes between simple and complex ideas but does not develop a formal theory of psychological association. The doctrine of associationism emerged later in the 18th century, with David Hartley's 'Observations on Man' (1749) providing the first systematic psychological account of association.

John Locke laid the groundwork for empiricist associationism and coined the term “association of ideas” in a chapter he added to the fourth edition of his *Essay Concerning Human Understanding* (1700). ... Thus, despite the significance of his work in setting the stage for later associationists, Locke does not treat association as explaining the mind in general. He treats it as a failure to reason properly... For these reasons, some have questioned whether one ought to treat Locke as an associationist... Hartley's most important contribution is the very project of describing an entire psychology in associative terms. This animated the associationist tradition for the next hundred years or so.

It is commonly acknowledged that associationism took hold after the publishing of John Locke’s *Essay Concerning Human Understanding* (1690/1975). However, Locke’s comments on associationism were terse (though fertile), and did not address learning to any great degree. The first serious attempt to detail associationism as a theory of learning was given by Hume in the *Treatise of Human Nature* (1738/1975).

He introduced his major work in 1749, **Observations of Man**, with the forthright statement, "Man consists of two parts, body and mind." The beginning of the work presents Hartley's theory of **association** based on physiological vibrations in the nervous system.

Locke thinks that sensation and reflection are our only sources of ideas. Locke argues that ideas of secondary qualities do not resemble anything in the objects that 'have' them, and secondary qualities depend on primary qualities. Locke emphasizes that general and universal concepts belong not to the real existence of things but are inventions of the understanding made for its own use.

Several distinct themes are present, the first and most fundamental element being John Locke's assertion that knowledge was based upon sensation. David Hume further developed this simple statement... Hartley's description of madness was this very similar to that of Locke, but differed in its more physiological, organic emphasis.

In 1749 David Hartley published his **Observations**, a work of great historical significance, yet the history of the Observations has been frequently debated. Hartley is recognized as the founder of **associationist psychology**, building on ideas from John Locke.

Observations on man, his frame, his duty, and his expectations. In two parts. By David Hartley. Published in 1749. This primary source confirms the publication date and authorship of Hartley's work on human nature, which develops **associationism**.

Observations on man:: his frame,his duty,and his expectations (1749). This is a digitized version of David Hartley's 1749 publication, foundational for **associationist psychology** extending Locke's ideas on the association of ideas.

John Locke (1632-1704) rejected associationism but conceded that learning by association does occur. His consideration of associationism was an afterthought, employed mainly to understand errors in reasoning... For the British empiricists (e.g., Berkeley, Hume, Hartley, James Mill, John Stuart Mill, Bain)... associationism played a much larger role.

However, it seems that with Hartley, associationism changed from being a component of empiricist epistemology to being basically a psychological doctrine on its own... Philosophical associationism reached its... At about the same time Descartes popularized the doctrine of innate ideas (and relegated associationism to a purely neurological doctrine).

SUMMARY OF ENGLISH ASSOCIATIONISM. 1. Development of the Association Concept from Hobbes to Hume, 154. 2. Contributions of Hartley and Brown, 157.

Title, A History of the Association Psychology; Author, Howard Crosby Warren; Edition, reprint; Publisher, C. Scribner's sons, 1921.

Observations on Man, His Frame, His Duty, and His Expectations by David Hartley, published 1749. The work systematically develops theories of **association** in psychology, directly referencing and extending principles from Locke's Essay Concerning Human Understanding.

John Locke's 'An Essay Concerning Human Understanding' (1689, Book II, Chapter 33) introduces the concept of the **association of ideas**, where ideas become connected by chance or custom rather than natural relation, laying the groundwork for associationist psychology later formalized by David Hartley.

The volume under notice, by the well-known professor of Princeton University, contains a great deal of matter which cannot fail to be useful to the student...