Explain and Critically Discuss Hume’s Distinction Between Impressions and Ideas

The distinction with regard to the different degree of vivacity that they display is claimed by Everson “to be false and carelessly executed.” (1988: p1) This is for two reasons. First, it is significant that the different in vivacity-degree is always a phenomenological one. In other words, impressions and ideas “appear different” (Noonan 1999: p61) and the difference between them is not solely shown in their causal origin. Secondly, it is important that the vivacity-degree also distinguishes between “belief and mere thought.” (Noonan 1999: p61)

This claim is supported by Hume’s definition of a belief as “a lively … idea associated with a present impression” (Inquiry 1975: 2) coupled with his account that a belief is the result of the transmission of vivacity from an impression to a corresponding idea through the copy principle. In other words, Hume states we attribute reality to those impressions that strike us with the most vividness; we then associate these with corresponding ideas due to a second “system of perceptions” in which we subsequently also believe.

Another criticism of this distinction focuses on the imagist theory of thinking. It contends the assumption that the work of concepts – which is what ideas carry out according to Hume – is always performed by images. This argument follows the Wittgenstinian belief about thought. In his Philosophical Investigations, Wittgenstein writes that “if God had looked into my mind he would not have seen there of whom I was thinking.” (1968: p217) This could be interpreted that either the picture he had in his mind could be misconstrued, or that no image is necessary at all for one to think specific thoughts. If the latter is considered to be true, then (referring to the past example of a tree) a picture of a tree does not necessarily pass through the mind’s eye when I think of it. If an image of a tree is not in my mind when I think of it, then there must be more differences between impressions and ideas that have not before been considered.

Similarly, suppose a particular passion does take the form of an image in the mind’s eye. The image could be more or less inherently vivid than the passion was at the time of its occurrence. Surely no vivacity-degree could provide it with a reference beyond itself because to be an image of a passion, it must be construed as a representation. In other words, the image would have to give rise to a belief in the reality of what it symbolises. This can be shown by the example of memory, which according to Hume, is “betwixt an impression and an idea” (Treatise 1978: with regard to its vivacity-degree.

I could have the memory of being in love, which would be less vivid than actually being in love. When discussing such a memory with another person, I would have to explain to them an idea of being in love. Such an idea would – according to Hume – present itself to the other person as a symbol of “being in love”: an image which could be entirely different to the original impression that sits in my memory. The point is that the imagist theory of thinking does not seem to be a rational explanation of ideas of passions and sensations.

Thus, it would seem that Hume’s distinction between impressions and ideas could be classed as an inadequate explanation of perceptions. Although he asserts his views again and again that impressions are “lively and strong,” while ideas are “faint and languid,” (Treatise 1978: he does not respond sufficiently to the criticisms mentioned above. Finally, his “extraordinary insensitivity to consistency” (Passmore 1952: p131) means that attempting to obtain a methodical theory of mind, especially when he seems to ignore certain problems, is an extremely difficult assignment.