(b. Armley, Yorkshire, England, ca. 30 August 1705; d. Bath, England, 28 August 1757)
Hartley was born into the family of a poor Anglican country clergyman in Yorkshire. His mother, Evereld Wadsworth, died in the year David was born. His father, also called David, then married Sarah Wilkinson in 1707, by whom he had four children, but he too died while David was still a boy. After being brought up “by one Mrs. Brooksbank,” Hartley attended Bradford Grammar School and in 1722 entered Jesus College, Cambridge. He studied classics, mathematics, and divinity and received his B.A. in 1726 and his M.A. in 1729. He was a fellow of Jesus from 1727 until he took leave in 1730. When he married a year later, his fellowship was terminated in accordance with the college statutes.
Although devoutly religious, Hartley had scruples against signing the articles and went into medicine instead of taking orders. He never obtained a medical degree but went to study in Newark, where he also began his practice. He then moved to Bury St. Edmunds. In 1735 he married for a second time and his wife’s private fortune enabled them to settle in London. But her ill health required them to move to the health spa of Bath, where they remained until his death. His son David became a statesman and inventor.
Although Hartley was a fellow of the Royal Society, the center of his life was his medical practice, not science. He lived a simple life, devoted to the health of both rich and poor. He was an amiable and methodical man with a wide circle of friends that included Stephen Hales, bishops William Law and Joseph Butler, and Sir Hans Sloane. During his lifetime he championed a variety of causes, among them Mrs. Stephens’ bogus cure for the stone (from which he had suffered as a young man), John Byrom’s shorthand system, and Nicholas Saunderson’s algebra textbook.
Hartley wrote one important work, Observations on Man, His Frame, His Duty, and His Expectations, which appeared in two volumes in 1749. It contained a systematic development of ideas which he had first set out in a pamphlet, Conjecturae quaedam de sensu mortu et idearum generatione (1730), and which were developed further in two small treatises on The Progress of Happiness Deduced From Reason (1734). The argument of Hartley’s Observations brings together ideas from three main sources. The first is the principle of the “association of ideas” as described in the fourth edition of Locke’s Essay: that complex ideas are formed from simple ones by repeated juxtapositions in experience. This concept had been elaborated by the Reverend John Gay in his “Preliminary Dissertation Concerning the Fundamental Principle of Virtue or Morality” (Cambridge, 1731), in which Gay attempted to deduce all man’s intellectual pleasures and pains frøm the principle of association, in opposition to innatist theories of learning and morality.
Hartley tried to relate these speculations to a theory of the physical basis of sensation and memory derived from the “Queries” appended to Newton’s Opticks. Newton had speculated that physical vibrations of light impinged on the retina of the eye, setting up other vibrations which traveled along the nerves to the brain. Locke’s preoccupations had been epistemological, Gay’s ethical, and Newton’s physical. Hartley’s synthesis attempted to integrate these three approachs by relating natural theology to the problem of providing a naturalistic basis for morality. He was thus led to work out a systematic psychophysiology.
The first volume of Observations is a tour de force which considers every significant topic in neurophysiology and human and comparative psychology, explained in terms of the development of complex ideas and habits from simple sensations and their repeated juxtapositions in experience. Mental associations were paralleled by vibrations of particles in the nervous system that persisted in the form of smaller “vibratuncles” which provided the physical basis for memory. The second volume extends the system to account for morality and the afterlife.
The significance of Hartley’s work did not lie in any new empirical findings but in a set of assumptions and a framework for approaching the phenomena of life and mind. In the century following the publication of Observations, the work came to be seen as the fountainhead of some of the most important ideas in biological, psychological, and social thought. Viewed in a narrow perspective, it was the first published work in English to use the term “psychology” in its modern sense. Hartley’s principles provided the conceptual framework for the associationist tradition in modern psychology, including learning theory and psychoanalysis. His speculations about the physiology of the nervous system laid the foundations for the dominant sensory-motor interpretation of neurophysiology and the experimental localization of functions in the cerebral cortex.
It is misleading, however, to separate the psychophysiological from the more general aspects of Hartley’s influence. His book is the central document in the history of attempts to apply the categories of science, both directly and by analogy, to the study of man and society. Much of the nineteenth-century debate in Britain on man’s place in nature was conducted under its influence. Considered conceptually, Hartley’s was the first systematic elaboration of the explanatory principle that came to play an analogous role in the biological and human sciences to the concept of gravity or attraction in the physicochemical sciences. His unification of sensation, motion, association, and vibrations in a coherent mechanistic theory of experience and behavior provided the grounds for the secularization of the concepts of adaptation and utility. This secularization was taken up in a wide range of disciplines as a basis for accounting for cumulative ordered change through experience. It was used as a general warrant to explain changing utilities and adaptations by means of the pleasurable and painful results or consequences of actions.
Hartley’s influence is perhaps best understood through the work of later theoreticians. Joseph Priestley, for example, stressed Hartley’s determinism but set aside his psychophysical dualism in his publication of Hartley’s Theory of the Human Mind (1775). This reductionist version of Hartley’s theory was then placed in the service of Priestley’s Unitarian philosophy of nature. Erasmus Darwin used Hartley’s mechanisms as the basis for his theory of evolution and for his system of medical classification in Zoonomia (1794-1796). In social and political theory, William Godwin’s arguments for inevitable human progress toward perfection in Political Justice (1793) were based on extrapolations from Hartley’s ideas. The psychological, social, and political theories of the English utilitarians—especially James and John Stuart Mill—were also based on Hartleian psychology and generalizations from it.
Between 1830 and 1860 there was a convergence of various aspects of Hartley’s influence. Müller drew on Hartley’s motor theory of learning, which was by then gaining support from findings in experimental neurophysiology. In formulating his physiological and psychological theories Alexander Bain integrated Hartley’s sensory-motor physiology with the mainstream of the English tradition of associationist psychology. Theories of evolution also drew on Hartleian mechanisms. Thus, Spencer’s evolutionary theory extended associationist learning theory from the experience of the individual to that of the race. J. Hughlings Jackson applied these conceptions to the physiology and pathology of the brain, while David Ferrier applied them to the experimental localization of cerebral functions.
What had begun as the integration of corpuscular physics with empiricist epistemology and sensationalist psychology was thus reinterpreted in biological, evolutionary terms to provide the foundations for modern theories in biology, neurophysiology, human and comparative psychology, neurology, psychiatry, psychoanalysis, social and political theory, and belief in progress. It has been argued that Hartley’s is the only theory of learning that has borne fruit in modern science. The list of disciplines based wholly or in part on the principles which he formulated provides some indication of the fecundity of his ideas in the history of the reification of man.
I. Original Works. Hartley’s significant works are Conjecturae quaedam de sensu motu et idearum generatione (London, 1730; 2nd ed., Bath, 1746), repr. in S. Parr, ed., Tracts (London, 1837); and Observations on Man, His Frame, His Duty, and His Expectations, 2 vols. (London, 1749). His clinical medical papers are listed in the Dictionary of National Biography, XXV (London, 1891), 68.
II. Secondary Literature. For information on Hartley or his work, see G. S. Bower, David Hartley and James Mill (New York, 1881); S. T. Coleridge, Biographia Literaria (London, 1817), chs. 5-7; E. Halévy, The Growth of Philosophic Radicalism, rev. ed. (London, 1952), pp. 5-34, 193, 247, 433-487; G. H. Lewes, Biographical History of Philosophy, 2nd ed. (London, 1857), pp. 507-511; J. Mackintosh, “Dissertation Second: Exhibiting a General View of the Progress of Ethical Philosophy, Chiefly During the Seventeenth and Eighteenth Centuries,” in The Encyclopaedia Britannica, 8th ed. (Edinburgh, 1860), I, 378-386; J. S. Mill, “Bain’s Psychology,” in Edinburgh Review, 110 (1859), 287-321; G. Murphy, Historical Introduction to Modern Psychology, 2nd ed. (New York, 1949); R. C. and K. Oldfield, “Hartley’s ‘Observations on Man,’” in Annals of Science, 7 (1951), 371-381; Joseph Priestley, Hartley’s Theory of the Human Mind (London, 1775); T. Ribot, English Psychology (London, 1873), pp. 35-43; H. C. Warren, A History of the Association Psychology (London, 1921), pp. 50-80; and R. M. Young, “Association of Ideas,” in P. P. Wiener, ed., Dictionary of the History of Ideas (New York, in press).
Robert M. Young
David Hartley (1705–1757), called the father of British psychology, was indeed the first to use the word “psychology” in its modern sense. He attempted a comprehensive interpretation of psychological phenomena based on the observation of behavior, bearing in mind its physiological substrate. His Observations on Man: His Frame, His Duty and His Expectations (1749) sets out a philosophy of human life in terms of a special theory of association. It is as the first comprehensive “associationist” that Hartley is chiefly remembered in histories of philosophy and psychology. But he also deserves study for his general method and his grasp of the special complexities involved in any attempt to elucidate mental processes by reference to physiological mechanisms.
Hartley’s theory of association is derived from Locke’s Essay Concerning Human Understanding (1690) and John Gay’s preface to King’s Essay on the Origin of Evil (King 1702). Parallel to the formulation in terms of the association of ideas and equally important is his physiological theory. This avowedly hypothetical physiology is based on Newton’s suggestion that the sensation of seeing comes from “vibrations, being propagated along the solid Fibres of the optic Nerves into the Brain…. For because dense Bodies conserve their heat a long time …the Vibrations of their parts are of a lasting nature, and therefore may be propagated along solid Fibres of uniform dense Matter to a great distance, for conveying into the Brain the impressions made upon all the Organs of sense” (Newton  1952, Query 12, p. 345). Hartley was thus among those who denied the view, then commonly held, that the nerve fibers are hollow and allow the transmission of influence by flow of animal spirits. He thought such vibrations might underlie the transmission of all sensory and motor messages to and from the brain and considered how the resulting cerebral activity might represent the whole variety of human experience. He supposed that all coding and decoding of both sensations and ideas take place within the “medullary substance” of the brain—that is, the white matter —and that “Vibratiuncles“—miniature vibrations that correspond to the incoming vibrations of sensation—are generated and persist there, giving rise, by combination and contiguous association, to memory and ideas. He illustrated and tried to test these suppositions against his own observations of human and animal behavior, ranging from “auto matic actions” (that is, reflexes) such as respiration and digestion to such “ideas of intellect” as “theopathy.”
For this ambitious and possibly premature undertaking, Hartley had good qualifications. Son of a country clergyman, a scholar of Jesus College, Cambridge, he studied classics, mathematics, and divinity, intending to take holy orders. Doctrinal scruples caused him to turn instead to medicine. While a fellow of Jesus College, he came across Gay’s suggestion of the all–pervasive power of association and elaborated on this theme in a brief pamphlet, Conjecturae quaedam de sensu, motu, et idearum generatione (1730). All his further work was devoted to the development of the ideas here outlined, and he determined to try physiological and philosophical theory “to give guidance to the art of ethics and customs.” Nineteen years elapsed before the publication of his magnumopus. During this time he was occupied with a medical practice among rich and poor, with family life, and with the cultivation of numerous friends. Among his intimates were Stephen Hales, Sir Hans Sloane, William Cheselden, Bishop Butler, and John Byrom. He was elected fellow of the Royal Society in 1743. Always receptive to other people’s ideas, he was courageous, if not always discreet, in trying out new ones, and his contemporaries did not take him quite seriously as a philosopher or scientist.
The Observations seems to have made little impression at the time of its publication. Joseph Priestley, however, who found the implied necessitarianism congenial, republished the work in 1775, omitting all the physiological parts, which he regarded as valueless speculation. Hartley’s theory of association became the major influence on the English empiricist school of the nineteenth century, notably in the psychological works of the Mills and Alexander Bain (Warren 1921; Ribot 1870).
Although there is little in Hartley’s work that directly influenced his immediate successors, it still bears examination for its freshness of outlook and catholicity of interest. Hartley wove into his formal argument a mass of material whose relevance to the science of psychology has progressively in creased since his day. Parallel to the analysis of consciousness, from primitive sensations to ab stract ideas, runs an account of the evolution of behavioral mechanisms, from the simplest “automatic actions” (reflexes) through the “secondarily automatic actions“—that is, basic muscular skills such as walking, whose character Hartley was the first to define and comment on—to the supposed cerebral concomitants of such “mental” skills as thinking. The reflexes, of course, derive from Descartes (1662). Of particular interest is the analysis of the mechanics of habit, which Hartley evidently gained from some lesser known passages in Male–branche’s De la recherche de la verite (1674–1675). In his account of the higher mental functions, Hartley revealed the considerable influence of the work of John Wilkins, bishop of Chester, on language (1668). Thus, his theory of memory relies on the “perpetual recurrency of the same impressions, and clusters of impressions” which come to form “the rudiments or elements of memory” in the same way as letters of the alphabet form the rudiments of language (1749, part 1, pp. 374–375). Similarly, his discussion of conjecture and hypothetical thinking draws on the work of Abraham de Moivre (1718) and other contemporary mathematicians who were concerning themselves with the practical aspects of probability theory.
It was from Thomas Willis (1664; 1672) that Hartley gained the knowledge of the anatomy of the brain which brought him close to a post–Darwinian view of the relation of man and animals. “The brute creatures,” he wrote, “prove their near relation to us, not only by the general resemblance of the body but by that of the mind also” (1749, part 1, pp. 413–414). Hartley was led, on the basis of the very meager information available, to a primitive doctrine of the localization of cerebral function. This preoccupation passed out of psychology and neurology and, in the form in which he stated it, only reappeared in late nineteenthcentury experimental and clinical studies of brain function. Nor had Hartley neglected that other preoccupation of nineteenth–century medicine, the hysterical disorders.
Hartley’s theology, sometimes trite and always constrained by contemporary Biblical interpretations, is nevertheless nodal to his philosophy as a whole. It was his primary concern to provide religion with a natural and scientific basis through a genuinely psychological analysis of religious experience. Hartley regarded the second (and much longer) part of the Observations, devoted to man’s “Duty and Expectations,” as interdependent with the first. He seems to have perceived that his attempt did not wholly succeed, but he pressed the laws of mechanism as far as they would go. “All the evidences for the mechanical nature of body and mind,” he wrote, “are so many encouragements to study them faithfully and diligently, since what is mechanical may be both understood and remedied” (1749, part 1, p. 267). Later psychologists have increasingly adopted this principle of method, even if some, like Hartley, have remained aware of elements in human consciousness that are resistant to it.
Kathleen C. Oldfield
[For the historical context of Hartley’s work, see the biography ofLocke; for discussion of the subsequent development of Hartley’s ideas, seeNervous System, article onStructure and Function of the Brain; Stress.]
(1730) 1837 Conjecturae quaedam de sensu, motu, et idearum generatione. Pages 143–185 in Samuel Parr (editor), Metaphysical Tracts by English Philosophers of the Eighteenth Century. London: Lumley.
(1749) 1834 Observations on Man: His Frame, His Duty and His Expectations. 6th ed., corr. & rev. London: Tegg.
Descartes, Rene 1662 De homine. Lugduni Batavorum (now Leiden): Moyardus & Lessen.
King, William (1702) 1732 An Essay on the Origin of Evil. Preface by John Gay. 2d ed. London. →First published as De origine mali.
Locke, John (1690) 1959 An Essay Concerning Human Understanding. 2 vols. New York: Dover.
Malebranche, Nicolas 1674–1675 De la recherche de la verite. 2 vols. Paris: Pralard.
Moivre, Abraham de (1718) 1756 The Doctrine of Chances: Or, a Method of Calculating the Probabilities of Events in Play. 3d ed. London: Millar.
Newton, Isaac (1704)1952 Opticks. New York: Dover.
Oldfield, R. C; and Oldfield, Kathleen C. 1951 Hartley’s Observations on Man. Annals of Science 7:371–381.
Priestley, Joseph 1775 Hartley’s Theory of the Hu man Mind, on the Principle of Association of Ideas. London: Johnson.
Ribot, T. (1870) 1873 English Psychology. London: King. → First published in French.
Warren, Howard C. 1921 A History of the Association Psychology. New York: Scribner.
Wilkins, John 1668 An Essay Towards a Real Character and a Philosophical Language. London: Gelli–brand.
Willis, Thomas 1664 De cerebri anatome cui accessit nervorumque descriptio et usus. London: Roycroft.
Willis, Thomas 1672 De anima brutorum quae hominis vitalis ac sensitiva est…. Oxford: SHelden.
English Physician and Philosopher
David Hartley was an English physician who developed an influential philosophy of thinking known as associationism. Hartley strove to explain how the mind and consciousness functioned; and he speculated that the mind is able to work by the association of sensations and the cumulative experiences of life, or memories. Hartley was also influential in suggesting that the mind and body do not function independently of each other but work together in concert.
Hartley was the son of a poor Anglican clergyman; his mother died before he was a year old and his father died while he was a young boy. He entered Jesus College, Cambridge, in 1722 where he studied mathematics and divinity; he received his Bachelors in 1727 and his Masters in 1729. This course of education would have led to a career in the Anglican ministry, but Hartley was not willing to sign his commitment to the Thirty-nine Articles on the Church of England. Thus, having abandoned the ministry, he turned to medicine.
Hartley never obtained a degree in medicine, but he started his medical studies in Newark where he then began to practice. He later practiced medicine in Nottinghamshire, London, and finally Bath, where his second wife could take advantage of the nearby health spa for her illness. Hartley remained in Bath until his death.
Hartley's major work, Observations on Man, His Frame, His Duty, and His Expectations, was published in 1749 in two volumes. In this work, he further developed a concept from John Locke's Essay Concerning Human Understanding, namely that complex ideas are the result of simpler, earlier ideas tempered with memories and experience. Hartley then joined this idea with a concept of memory and sensation from Isaac Newton's Opticks in which Newton theorized that the vibrations that make up light entered the eye and traveled by way of vibration to the brain where they are recognized as light. Hartley forwarded the idea that all mental processing, especially that of memories, is based on vibrations in the brain and spinal column. The very existence of memories was based on "vibrantuncles," as Hartley called them, which resulted from the vibrations entering the brain from experiences. In this way, Hartley was able to formulate his idea that memories and experiences work together to make the brain operate.
The significance of Hartley's work Observations was realized later as other thinkers and scientists used his concept of associationism to explain psychological, social, and physiological concepts. Hartley wrote Observations intending it to be considered a work of philosophy, but it has been that and much more. Hartley's idea that things work together in order to function properly opened a floodgate of ideas that were cultivated by later scientists in areas such us biology, evolutionary theory, neurophysiology, psychiatry, social theory, and neurology. Hartley was the first to use the term "psychology" to describe the study of behavior and brain functioning.
Hartley's concept of association can be easily seen in use with the psychotherapeutic tool "free association" in which a patient reports the first image that comes to mind when the therapist says a random word. Brainstorming, an idea generating tool used in advertising and business, has its roots in associationism. Hartley's work Observations, based on his speculations regarding the functioning of the brain, is regarded as one of the pivotal pieces in the foundation of modern science, if not expressly for the principles of associationism.
MICHAEL T. YANCEY
The British physician and philosopher David Hartley (1705-1757) is often referred to as one of the fathers of physiological psychology.
David Hartley, the son of a British clergyman, was born on Aug. 30, 1705. He received a private education before attending Cambridge, where he earned a bachelor's degree in 1726 and a master's degree in 1729. Although he intended to follow his father into the clergy, Hartley's disagreement with certain speculative doctrines adhered to by the Church of England prevented him from doing so. It did not, however, prevent him from remaining a lifelong member and defender of the Church or from writing on the subjects of theology and morals, as well as medicine and psychology. Forced to seek a new profession, Hartley turned to medicine and enjoyed considerable success.
Often the major contributions of self-effacing men are known best to those who come after them. Hartley's reputation as one of the founding fathers of the science of psychology rests on his two-volume work, Observations on Man, published, almost unnoticed, in 1749. Volume 2 deals with theology, and though of great importance to its author, it is of historical significance only as an example of the conviction held by many 18th-century scientists that there was no necessary conflict between science and revealed religion. Volume 1 is a systematic description of the emergence of highly complex emotional and mental states out of simple physical sensation.
Hartley's psychology can best be summarized under the twin headings of physiological determinism and associationism. All ideas and emotions are merely the coming together, or association, of various separate ideas which in turn can be traced to individual sensations that have been transmitted along the various nerves by a process of physical vibrations.
Hartley's private life was relatively uneventful: twice married, he fathered a number of children. Though he made little impression on the contemporary world at large, he communicated with many first-rate English minds of his day. In every way a gentleman, he was a kindly and expert doctor, well versed in subjects as diverse as shorthand and poetry and mathematics, devoutly religious, well organized and methodical though neither pedantic nor coldly efficient, and loved and admired by all who knew him. Hartley died at Newark, London, where he had practiced medicine, on Aug. 28, 1757.
The Transactions of the Halifax Antiquarian Society (1938-1939) contains a series of letters from Hartley to John Lister. These letters include personal information and show his interest in theological matters as well as algebra and shorthand. A facsimile of the first edition of Hartley's Observations on Man, edited by Theodore L. Huguelet (1966), contains a 12-page introduction which discusses Hartley's influence and life. □