Hume questions 2

Here are some bloggable questions that occur to me as I read the Enquiry, sections 3-5.

Re section 3:

01 Hume refers to a "universal principle" that led to the appearance of all the diverse languages spoken by various peoples in the section's opening paragraph. He says too little about his idea, but I'm curious what he has in mind here. Is language merely a moving around of relations of ideas, and so the principle in question is a principle of logic and the a priori operations of mind? But then how did it lead to empirical facts about language varieties? Or is language a tool for expressing our impressions to others, and thus is sort of a posteriori, sort of a priori?

Re section 4:

01 A homework assignment that grew from the discussion in the room today: does Hume think of impressions as simple? complex? both? Does it matter to his epistemology to sort impressions using simple/complex criteria?

02 Does agnosticism about causal relations entail any substantive claims about those relations? (That is, are we entitled to conclude anything about the real nature of cause and effect from the fact (if it's a fact) that we cannot discover causal information?)

03 Hume's short list of "ultimate springs and principles" near the end of Part 1 includes "elasticity, gravity, cohesion of parts, communication of motion by impulse". What kind of list is this? Are these old-timey versions of what physicists think of as the Standard Model? Or is it meant to be more of a list of what ordinary observers would marvel at in the realm of physical events that occur in everyday life?

04 One of Hume's central doctrines is that we cannot discover causal relations via impressions; that's clearly what his range of examples is supposed to show (bread, billiard balls, etc). But in part 2, Hume glosses his doctrine in a slightly different way: "As to past Experience, it can be allowed to give direct and certain information of those precise objects only, and that precise period of time, which fell under its cognizance: but why this experience should be extended to future times, and to other objects...." The problem here seems to be not about causal relations, but about our knowledge of object and other, as well as our knowledge of past and future times. So an intriguing question: is causal information non-discoverable because object-other information is non-discoverable? Or perhaps because past-future information is non-discoverable? (Which thing can't we know via impression that leads us to miss out on natural patterns?)

Re section 5:

01 Hume's theory of belief (discussed in part 2) is quite naturalistic: "belief is nothing but a more vivid, lively, forcible, firm, steady conception of an object, than what the imagination alone is ever able to attain." So is it possible to have a belief about something as a result of reasoning?