This paper aims to clarify some of the intentions of Hume's arguments concerning the mind-body problem in his Treatise of Human Nature, I, iv, 5. It attempts to examine three main things: (1) the features of Hume's arguments compared with those of Locke; (2) Hume's own use of the words, such as ‘notion’, ‘fiction’ or ‘feign’, and ‘imagination’ or ‘fancy’; and (3) Hume's new method of explanation in terms of human nature on the problem concerning a conjunction of mind and body in place. In the course of these examinations, it will be shown that Hume's sceptical arguments suggest a new solution on the problem concerned, and lead to the naturalism, presented in the light of human nature.