In answering this question, it is important to consider Hume's basic skepticism, and to consider that he started from an Empiricist position, (which you would need to identify) but soon found that he could not get certainty from simple observation of the world. This leads him to some interesting dead ends. The basic source for most of this information is in his "Inquiry Concerning Human Understanding" Here is a link:http://18th.eserver.org/hume-enquiry.html#7. The relevant chapters that relate to this questions are particularly, sections IV and VII.
In discussing Hume's causation, you need to consider that he is looking at what we see, and what we see is "constant conjunction"-thing A happens and then thing B happens, and from that we conclude that A has caused B. The problem is, of course, that we cannot see A causing B-and that our belief in this relationship comes from another untenable belief, which is, simply put, that if something happened before it will continue to happen in the same way. But of course, it is possible (or perhaps a better word is "conceivable") that things will change. Most of this is in ...
The solution provides advise in the ideas proposed by David Hume, especially that in relation to skepticism and his rejection of causation, self, soul and the existence of God.