What is Hume’s hypothesis of the double relation of impressions and ideas from which a passion arises? How does it operate in structuring his system? These are primary questions that need to be answered in order to understand Hume’s intention in the Treatise. Yet, there exists no reasonable answers, nor serious attempts to answer them, probably because this hypothesis is considered as a limited issue, relevant only to the indirect passions, or because it is too mechanical and unsophisticated to excite critics’ curiosities. My present aim is to show that Hume’s double relation of impressions and ideas operating in the production of indirect passions is integral to his entire system not only in that it serves as a powerful weapon to advocate his naturalistic position, but also in that it is a highly sophisticated psychological mechanism that functions as a schema for the cooperation of the imagination and the passions.

The purpose of Hume’s argument about induction, contra “literalist” interpreta­tions that see it merely as psychology, is to show that induction cannot be justified. Hume maintains that the only way to justify induction would be to demonstrate or to produce a good inductive argument for the uniformity principle (UP). His most famous point is that any attempt to justify UP inductively would be circular. One may retort that no inductive argument can be circular, for a circular argument must be deductively valid. But there is a sense in which a purely inductive argument for UP is circular: it uses induction for the purpose of justifying induction. Therefore, the literalist interpretation cannot be right. For if the argument can be circular only if its purpose is to justify induction, and Hume has shown that it is circular, then its purpose must be to justify induction, and Hume shows that this cannot be done.

The question broached in the title may sound odd. It makes sense to ask whether Hume’s empiricism is successful, and whether it is the best way of rendering rigorous the (vague) empiricist view. But is it not obvious that Hume is an empiricist? I shall argue that the answer is negative, at least when we are concerned with method­ological empiricism, pertaining to the way inquiry, both scientific and philosophical, must proceed. In support of my claim, I will distinguish between the theoretical ques­tion, pertaining to the methodological view Hume endorses, and the practical ques­tion, concerned with the way he conducts his inquiry. My conclusion will be that the answer to the first question is contentious, and the answer to the second is negative.