Story of Psychology - Morton Hunt [54]
It is impossible, upon any system, to defend either our understanding or our senses…As the skeptical doubt arises naturally from a profound and intense reflection on those subjects, it always increases the further we carry our reflections, whether in opposition or conformity to it. Carelessness and inattention alone can afford us any remedy. For this reason I rely entirely upon them, and take it for granted, whatever may be the reader’s opinion at this present moment, that an hour hence he will be persuaded there is both an external and internal world.47
Hume’s devastating assault on the concept of causality is of great importance in the history of science, and nowhere more so than in psychology, which, struggling to become a science, was seeking to discover the laws of mental causation. Some psychologists in Hume’s time, and many later on, would therefore maintain that psychology cannot yield causal explanations and should attempt to deal only in correlations— the probabilities that two things will continue to occur together or in sequence. Ironically, the empiricism and associationism that Hume meant to be the foundation of his system of morals lives on; his system of morals, a gentle utilitarianism, is quite forgotten.
The Empiricist-Associationist School
Empiricist-associationist psychology disposed of some of the intractable problems in the theory of mind-body dualism and innate ideas, but in all sciences a new theory that answers old questions usually raises new and different ones. The new psychological theory not only led to subjectivism and cast doubt on the validity of causal explanations but, by reducing the major mental processes to perception and association, was able to say nothing illuminating about such high-level mental phenomena as consciousness, reasoning, speech, unconscious thought, problem solving, and creativity. It would, in fact, eventually prove most useful, in somewhat different form, as a theory of animal psychology.
Its simplistic explanation of how the mind forms abstract ideas worked well enough for concepts derived from perceptions, such as equality, but was unconvincing about those with no perceptual basis, such as virtue, soul, nonbeing, possibility, necessity, or the nondimensionality of a point in geometry.
Furthermore, except for Hobbes’s atomistic conjecture about nervous impulses, the new theory ignored the physiology of mental phenomena and could say nothing explanatory about reflexive reactions, let alone all those high-level automatic responses which make up much of everyday human behavior.
From Locke’s time on, a series of empiricist-associationists, mostly in Great Britain, sought to solve some of these problems, but with only minor success, if any. Nonetheless, some of their work represents courageous venturing into the unknown; if they crossed no uncharted oceans, some of them at least mapped a few miles of alien coastline.
David Hartley (1705–1757) was one of the latter. A scholarly physician, he was inspired by Locke’s work to write at length about associationism in his Observations on Man (1749). Although he added nothing original, his treatment of the subject was organized and systematic, and thereby, says the great historian of psychology, Edwin G. Boring, turned it into a “school.”48
In addition, Hartley, as a doctor, was sharply aware of Locke’s omission of physiology; he sought to present a more holistic psychology by discussing each phenomenon first in mental terms and then in physiological ones. An admirable effort; unfortunately, in the mid-eighteenth century the neurophysiology he offered was largely imaginary. From Newtonian physics he derived the idea that external vibrations in matter must cause corresponding vibrations of infinitesimal particles within the nerves. These vibrations produced miniature counterparts or “vibratiuncles… the physiological counterpart of ideas,”49 a pure figment of his imagination, yet a little closer to the truth than Descartes’ theory of hollow