Where does our idea of "power, force, energy or necessary connexion" come from?
Hume assumes a empiricists framework: every idea is ultimately derived from experience - in his words: "ideas are nothing but copies of impressions".
Three Taditional Answers
We get our ideas of causal power from experience of observing...
- The action of external bodies on each other, or
- The mind's ability to move the body at will, or
- The mind's ability to conjure up certain ideas at will.
Hume Will Reject All Three Traditional Answers.
Hume holds that experience in each of these three cases only ever shows us that certain regularities happen in fact to hold.
Whenever I observe a billiard ball stuck with sufficient force, I then next observe that same ball in motion.
But we only observe the constant conjunction or regularties of these event-pairs - we never actually observe any causal power by which the former causes the latter.
(1) We don't get our idea of causal power from observation of the behaviour of enternal physical objects (at least not "in single instances of their operation").
We don't experience causal power when we observe the actions of enternal objects (at least in single cases).
"We are never able, in a single instance, to discover any power or necessary connexion; any quality which binds the effect to the cause, and renders the one an infallible cosequence of the other. We only find, that the one does actually, in face, follow the other".
When we see an object (TH: event might be better?) for the first time, we can never foretell what will follow from it.
For all logic tells us, any event could be followed by any other event. Any succession of events is logically conceivable.
(2) We don't get our idea of causal power from observation (via internal reflection) of the operation of the mind in moving the body.
We don't experience causal power when we introspect on the mind's own ability to produce action.
"That [the limbs] motion follows the comand of the will is a matter of common experience, like other natural events; but the power or energy by…