Dr. Ari Santas’ Notes on

Hume’s Enquiry, Section II: Of the Origin of Ideas


A.     Goal of the Section

·  A fundamental precept of Empiricism is that all ideas - including abstract ones (like triangles) - are derived from experience

·  Contrast to the doctrine of innate ideas (senses are untrustworthy - legitimate ideas are already in us)

·  Hume, being in this tradition, believes that ultimately, anything we ever conceive of derives from experience

·  So, in his study of human nature, Hume is going to examine and account for all of our ideas

·  To do this, he will turn his gaze inward and reflect on the operations of his own thinking.

      ·  Introspection as a method

·  Accordingly, the title of this section is Of the Origin of Ideas


B.     An Initial Distinction

·  Looking inward, Hume notices that there seem to be two different sorts of mental contents in his consciousness

      ·  Some of them appear with more force and vivacity

      ·  The mental perceptions that are more forceful are called IMPRESSIONS

      ·  Those that are less forceful are IDEAS

·  Impressions can be outward or inward, and are often termed sensations

      ·  Outward: colors, tastes, smells, heat, cold, etc.

      ·  Inward: anger, depression, hate, love, envy, etc.

·  Ideas are either copies of impressions or products of our imagination

      ·  Copies: our memory

      ·  Imagination: what we dream or daydream


C.     Bracketing Out the World

·  A contemporary school of psychology - phenomenology - is indebted to Hume for his approach to studying the world

      ·  It is called putting the world in brackets (E. Husserl)

·  This is precisely what Hume does when he distinguishes the mental perceptions the way he does - phenomenologically

      ·  Impressions appear more forcefully than ideas

      ·  Not that they are more real

                  ·  e.g., look at board; close eyes & remember - same

                  ·  e.g., think of last be sting - hurts?

·  Hume tries to make no commitments about what the world is like independent of the appearance

·  Denying casual theory of perception (as well as Platonism) - suspending metaphysics

·  All I know is what I experience!

D.     Caution on Terminology

      ·  Hume is using the terms differently than Descartes had - do not mix them up!


      Descartes                         Locke                                      Hume

      adventitions                        of sense                                    impressions


      invented                              of the intellect                           ideas



      innate[1]                                N/A                                         {category mistake[2]}



E.      The Boundaries of the Imagination

·  On a first glance, our imagination seems to have an unlimited capacity to conjure up any idea it chooses


·  We can conjure up countless images - centaurs, dragons, pegasus, talking horses


·  There is, however, a limit on what we can imagine - there is an order to the chaos


·  Take any idea, from dreams, fiction, or day dreaming, and you will see that it can be reduced to a combination of ideas arrived at trough impressions


·  Our imagination works by the following capacities:


      ·  Compounding - combine: golden mountain


      ·  Transposing - swap: James on stage, me in desk


      ·  Augmenting - enlarge: James 100ft tall


      ·  Diminishing - make small: Cindy 3 inches tall


F.      A Preliminary Model

      ·  Here then, is a model for the origin of ideas:


Simple        ŕ     Simple

Impressions        Idea

(a red patch)         (image of

                              a red patch)

                                                            Imagination    ŕ        Complex Idea

                                                            (Compound,                 (image of a red

                                                              Transpose,                   round thing)

Simple         ŕ                 Simple                      Augment,

Impression           Idea                          Diminish)

(a round                (image of

 contour)                 roundness)



Complex Impression                   ŕ               Complex Idea

            (a dog)                                                (image of a dog)


      ·  Some complex ideas come from complex impressions—directly from experience

·  Others come through the imagination which gets its data from experience—indirectly from experience


G.     Two Proofs

      ·  Hume offers two reasons why we should believe that this is a good model

            ·  That all ideas do ultimately come from experience, either directly or indirectly

1)      The analysis of any complex idea will show that it can be resolved into two or more simple ones copied from (sense) impressions

      ·  The idea of God comes from augmenting certain positive qualities without limit

2)      Whenever someone lacks a certain sense organ, it is impossible to have the relevant idea

      ·  Blind man can have no idea of redness

      ·  One exception: the missing blue patch


H.     Implications

·  The result of Hume-s thesis that all ideas ultimately come from impressions (directly or indirectly) is that: if we want to evaluate the worth of an idea all that we have to do is consider the source

·  Hume-s proposition: All ideas, especially abstract ones, are naturally faint and obscure. . .On the contrary, all impressions, that is, all sensations, either outward or inward, are strong and vivid.

·  Unlike Descartes, Hume believes sense experience is clear and distinct, but abstract ideas are obscure and confused!

·  Given this result, we can solve any philosophical dispute by considering the impressions from which the ideas are derived

·  If there is no direct impression, we can infer it is the product of a wild imagination




A.     The Origin of Ideas

·  Being an empiricist, Hume believes he can reduce all of our ideas to our impressions, either directly or indirectly

·  Ideas come from impressions directly as our mind automatically makes copies of impressions

·  Ideas come from impressions indirectly through the imagination as we take copies of impressions and put them together in various way:

      ·  Compounding

      ·  Transposing

      ·  Augmenting

      ·  Diminshing

·  This, according to Hume, can account for any idea anyone has ever thought of, and it is all ultimately grounded in experience

[1] If innate = preceded by no perception then impressions are innate and ideas are not

[2] Our capacity to have impressions and create ideas is innate