Reading Hume's Treatise again, I was startled by his subtlety. For Hume is quite the writer. Indeed, many distinctions up front. More to come after one has anticipated, by objection, exceptions to the terms and definitions previously laid out. 

Most importantly, he comes at the issue of our sense of causality numerous times. And from various angles. However, he comes at the issue far more times than, it seems to this perhaps naive reader, the angles he has on the issue. 

And then he comes at it again, time and again. 

After this becomes a bit amusing, one reads: "I am sensible, that of all the paradoxes, which I, have had, or shall hereafter have occasion to advance in the course of this treatise, the present one is the most violent, and that 'tis merely by dint of solid proof and reasoning I can ever hope it will have admission, and overcome the inveterate prejudices of mankind."

Comment: So it will be by 'reasoning and proof'. Now, what 'reasoning and proof' is going to be offered? He basically holds that necessary connections are those which obtain between ideas, and contingent connections are those that obtain between things. So, are we going to discover in our idea of "causality" the predicate "constant conjunction of two items"? Is he about explaining to us the concept of causality? Then we would come to a certain conclusion. If this will not take place, how shall we learn and accept his notion of causality?

Back to the text: "Before we are reconcil'd to this doctrine, how often must we repeat ourselves, that the simple view of any two objects or actions, however related, can never give us any idea of power, or of a connexion betwixed them: that this idea arises from the repetition of their union: that the repetition neither discovers nor causes any thing in the objects, but has an influence only on the mind, by that customary transition it produces: that this customary transition is, therefore, the same with the power and necessity; which are consequently qualities of perceptions, not of objects, and are internally felt by the soul, and not perceiv'd externally in bodies?" 

Indeed, if we cannot find the truth of the Humean concept by burrowing into the notion of causality, if he hammers it home to us repeatedly throughout the Treatise, we might eventually become accustomed to accepting it. But alas, nature and culture seem against Hume's task: "I am much afraid, that tho' the foregoing reasoning appears to me the shortest and most decisive imaginable; yet with the generality of readers the biass of the mind will prevail,and give them a prejudice against the present doctrine." 

The efficacity of Hume's labor, on the other hand, astonishes. And how quickly many were universally to apply this "concept" to the many different instances of what cannot be the same but only like. I have a sense he is smiling as he writes. Humorous. 

But once we accept this labor, we immediately reason with him, readily (within 10 pages), to those absurd or paradoxical beliefs such as (1) all causes are the same (i.e., but sine qua non), (2) something can just 'pop' into being w/o any cause (why not?), (3) anything may produce anything, (4) a set of logical rules utterly devoid of consideration of essences - geared rather to statistic / correlational appreciation of otherwise coincidental happenings, (5) that animals reason just as we do, (6) that we are but bundles of properties (good luck finishing the book), (7) that we cannot have reason to believe that X exists if we can't form an idea of X (idea being an image). 

So, what is it: Hume or Us?