Hume 102: Section II — outline of what Hume says

All perceptions of the mind can be divided into two classes on the basis of their different degrees of force and vivacity (liveliness).

1. “perceptions of the mind”
   • This refers to those mental experiences of which we are aware.
   • They take place entirely within our heads. There is no direct access to the outside world or perhaps even evidence of an outside world. It is as if all those mental experiences are on some kind of internal cinema screen. (although the cinema screen analogy is inadequate as it only covers visual perceptions.)
     
     
2. Hume appeals to experiences he believes everyone will acknowledge
   • Pain of excessive heat v. remembering or imagining that experience.
   • A real fit of anger v thinking of the emotion
   • The turmoil of being in love v knowing what being in love means.
     
     
3. The two classes of perceptions are given names:
   • Impressions (a term invented by Hume) are the vivid originals we experience when having sensations whether they seem to originate from within (e.g. emotions, pain, etc) or from without (things we see, hear, etc.)
     You need to be very careful to understand this term correctly. Today people might associate the word with having 'a vague impression'. Hume means almost the opposite. It is better to think of the impression made in wax when an old-fashioned seal is pressed into it.
   • Ideas are the faint copies we conjure up when we remember or imagine those impressions.
     
     
4. "The most lively thought is still dimmer than the dullest sensation.”
   • Exception: “when the mind is out of order because of disease or madness”.
     
     
5. The copy principle
   • Ideas are copies or impressions.
   • "our thought is a faithful mirror that copies its objects truly; but it does so in colours that are fainter and more washed-out than those in which our original perceptions were clothed."
     
     
6. Simple and Complex ideas
   • Complex ideas are required to explain how we can apparently imagine things we haven’t seen.
   • Simple ideas are compounded, transposed, augmented, or diminished to create complex ideas.
   • Examples: gold mountain & virtuous horse.
     
     
7. Hume’s two supporting arguments
   • Argument one: Consider any idea and it will be possible to analyse it to discover the simple ideas of which it is composed and the impressions on which those simple ideas have been based.
     • e.g. the idea of God, which comes from extending our existing ideas of goodness and wisdom.
     • This is an inductive argument—all ideas we have tried can be so analyzed so, therefore, all ideas can.
     • However, it can be regarded as setting a challenge for anyone to supply a counter-example.
   • Argument two: If the impression is absent then no idea can be formed.
     • Malfunctioning senses. A blind or deaf person cannot form certain ideas until the organs are restored to working order.
     • Absence of relevant experience. Hume gives both outward and inward examples:
       • Laplander or Negro has no notion of the taste of wine (if it is true that they have not tasted wine).
       • A gentle person has no idea of “determined revenge or cruelty” and a selfish person cannot easily conceive of friendship and generosity. (Hume admits that it may never be the case that feelings are absent in the same way that sense experience can be absent but suggests that the same phenomenon can occur but in a lesser degree.)
     • Absence due to species limitations. Animals have senses that we don’t have so we cannot form the associated ideas.
       
       
8. The Missing Shade of Blue — This is dealt with separately here and here.
   
   
9. Hume’s microscope.
   • Ideas can be confusing and mixed up with one another.
   • We can sometimes use language thinking it refers to a specific idea when it doesn’t.
   • We can use the distinction between impressions and ideas to clarify our thinking
   • “when we come to suspect that a philosophical term is being used without any meaning or idea (as happens all too often), we need only to ask: From what impression is that supposed idea derived? If none can be pointed out, that will confirm our suspicion ·that the term is meaningless, that is, has no associated idea·.”