Hume's Ideas

HUME'S IDEAS In the eighteenth century, there was widespread acceptance of a physiological basis for cognition. Some writers even argued for a rather detailed correlation between awareness and physiological changes, suggesting that (a) the former could be adequately explained in terms of the latter or, in some few instances, (b) that the former are the latter. David Hartley may come to mind as fitting one or the other of these alternatives , but Robert Hooke had earlier argued for ideas as brain impressions, as of course did Descartes in his early scientific treatises. There was also one medical doctor in the eighteenth century, Dr. Astruc, who seems (on the basis of what Chambers reports) to have attempted a very specific correlation between specific forms of awareness and specific states and changes in physiology. There were also writers in this century who warned against the dangers of using physical-object vocabulary when talking about the mind and acts of awareness. Berkeley is one such writer,- Thomas Reid at the end of the century traced, to the use of this vocabulary, what he took to be the indirect realism of the way of ideas. Hume is writing in both these traditions: the tradition of using physical language for characterizing mental operations and the tradition of physiological explanations and correlations. The phrase used by Alexander Pope and Hume, 'the anatomy of the mind', seems to be a mixed metaphor , but it is a phrase which I take as an indication that Hume is doing what we would call 'cognitive psychology'. Another phrase used by Hume (this time in the Enquiry) , 'mental geography', may capture his enterprise better: 'geography' still sounds physical, but it is modified by 'mental'. Hume is engaged in mental mapping. I want to take a look at the use of the term 'idea' in Hume's writing (mainly in the Treatise) in order to see 2. whether Hume's text enables us to say anything about the nature of his ideas, to discover what role they play in his mental geography. As far as I can determine, there are three possible candidates for the nature of ideas in Hume: images, brain impressions, and cognitive contents. The first of these is, I think, the standard reading of Hume's ideas. Professor Anderson has presented strong argument and evidence to support the second. I will be suggesting that the third is the best candidate, given the full range of the text of the Treatise. Of course, the correct answer 4 may be all three of these. The Treatise opens by dividing all perceptions of the human mind into two kinds. Impressions and ideas differ in the degree of force and liveliness with which they strike upon the mind. Even though the language of 'force' and 'liveliness' may be borrowed from physical talk, it is the mind, not the brain, on which perceptions strike. The examples of impressions are sensations, passions, and emotions. Ideas are said to be the faint images of these impressions in thinking and reasoning. The term 'image' throughout the eighteenth century never receives any clear explication. Its inheritance from optical treatises always hangs about it. We should look to the examples cited by Hume, in order to see whether we can construct a meaning for that term when used in these psychological contexts. Let us look first at his very first example of 'ideas': all the perceptions excited by the present discourse . (Tl) He explicitly excludes from these perceptions those which arise from the sight and touch, as well as the immediate pleasure or uneasiness his discourse may excite in us. The perceptions which are thus excluded are sensations and emotions, the impressions he has just distinguished. The only candidate left for ideas would seem to be what this discourse says, our thoughts about it, my understanding of what it says. The distinction is not one Hume thinks is difficult to follow: Every one of himself will readily perceive the difference betwixt feeling and thinking. (Tl-2) Last week I was sad, today I recall that feeling of sadness/ the difference between being sad and remembering that I was sad. Hume gives a different example: the perceptions formed when...