Dr. Ari Santas’ Notes on

Enquiry VII: Of the Idea of Necessary Connexion


Part I


A.     Problems with Moral Sciences

      ·  The mathematical sciences have advantages and disadvantages

            ·  Their advantage is consciousness of ideas and clarity in each step in reasoning

·  Their disadvantages lie in painfully long series of inferences to demonstrate the simplest truth

      ·  The moral sciences also have advantages and disadvantages

            ·  Their advantage is in quickness of inference (fewer steps)

            ·  Their disadvantage is in obscurity of ideas, ambiguity of terms

·  Hume wants to improve the moral sciences and claims that to do this we must clean up obscurities and ambiguities

·  In this section, Hume will use what he has learned of far to clear up our obscurities concerning our ideas of power, force, energy: necessary connection


B.     Setting Up the Problem

·  The problem confronting Hume is how to get clear on this idea of necessary connection that philosophers have been kicking around and have reached no satisfactory result on

·  To set up the solution to this problem, Hume appeals to what he has established in Section II

      ·  Recall that all ideas are ultimately based on our impressions

      ·  We cannot think what we have not first felt

·  We know that if any given idea is the source of confusion, we need to consider its source

·  So; the first question Hume will ask here is, is there an impression corresponding to our idea of necessary connections

      ·  If so, the idea has legitimacy

      ·  If not, it is the figment of our imagination

·  Recall that impressions are either internal or external


C.     External Impression?

·  We must first consider whether we have an external impression of necessary connection

            ·  Do we ever perceive the force, energy, power that connects the events?

      ·  Hume says no:

            ·  All that we ever perceive is one event followed by another

·  We experience conjoined events, but never the connection: we do not experience relations






            E1                                                        E2



Impression                                                  Impression

(light the firecracker)                                   (firecracker explodes)


                              No Impression



D.     Internal Impression?

·  We now must consider whether we have an internal impression of necessary connection

      ·  Do we ever perceive force, power, energy

1)      By noticing that our mind has power over the body?

      ·  Hume says no because…

a)      We do not know how the mind controls the body (knowing cause = knowing how it works);

b)      This power is quite limited to certain parts of the body, yet we do not understand why (if we did, we would know why it is bonded this way);

c)      We do not truly know the power since we do not understand all the causal links in the chain;

2)      By noticing that our mind controls its own activities?

      ·  Hume says no because…

a)      We do not know how this works either

b)      This power is also limited (cannot always control your thoughts)

c)      We again do not know all the causal factors involved

·  The Gist: we do not have an internal impression of force, power, energy either; we only perceive conjoined events


E.      A Rationalist Solution?

·  The fact that we cannot experience necessary connection between causes and effects has troubled philosophers for a long time

      ·  How, then, are things connected

·  The Rationalists of Hume-s day, following Descartes, had a solution, which was called occasionalism

·  The occasionalists believed that there were no causes or powers in things, that events were only brought together through the will of God

·  They held this with resolve to all forms of casusality:

1)      Between material events (body-to-body)

2)      Between mental and material events (mind-to-body)

3)      Between mental events (mind-to-mind)

·  In each case, it is God alone that brings them together; there are no real causes other than His


F.      Rejection of Occasionalism

·  These occasionalists were out to show how ignorant humans really are without a knowledge of God, and how powerful God really is

·  Hume asks, why does this account make God seem any more powerful (is it greater to be constantly intervening)?

·  But more importantly, this account does not make us any more immodest in our claims to knowledge:

1)      This position is incredibly bold in what it claims to know, especially if human reason is supposedly finite [a logical path to wonderland]

2)      After stressing our ignorance about the world, it proceeds to make claims about things we have even less reason to know

            ·  Have we left the pan for the fire?

            ·  How is it that we know divine cause?

·  An appeal to supernatural causes usually (if not always) indicates a lack of knowledge

      ·  Why do the planets not bump into each other?

                  ·  Because God made them that way


Part II


A.     No Answer Yet

      ·  So where do we get the idea of necessary connection?

·  We have neither an internal nor external impression of it, and appealing to divinities does not help us in this difficulty

·  Whether we are dealing with physical, psychic, or psycho-physical causality, all we ever experience is one event followed by another

·  Events seem loose and separate

·  Are we to conclude, then, that the idea is meaningless?

·  No…

·  Then what?


B.     Custom

·  The idea is not meaningless, though the meaning is different than commonly supposed

·  Recall how we come to infer effects  from causes:

·  We experience one event that had been constantly conjoined with another event and through habit we infer the latter from the former

·  The idea of necessary connection, then, is nothing more than a feeling, acquired through habit, that the consequent will follow, given its regular antecedent

·  We never get such an idea through a single instance, but only after and observed regularity - constant conjunction

·  Once we have it, we can draw inferences reasonably, though Reason is not present



C.     Two Definitions of Cause

      ·  Given all the analysis in the foregoing discussion we can give a definition of cause

      ·  A cause then is:

1)      An object followed by another, and where all the objects similar to the first, are followed by objects similar to the second

2)      An object followed by another, and whose appearance always conveys the thought of it to that other

      ·  This is all we can claim to know about causes

1)      Constant Conjunction

2)      Inference of Mind

      ·  And these components are the same for the relation between any kinds of events

            ·  Physical

            ·  Psycho-Physical

            ·  Psychical