Hume is obviously compelled to deny that we have any idea of the self as distinct from our perceptions. All our perceptions are distinguishable and separable, and we can discover no self apart from or underlying these perceptions. According to Hume, we tend to confuse the two ideas of identity and of a succession of related objects. For example, an animal body is an aggregate, and its component parts are constantly changing: in the strict sense it does not remain self-identical. But the changes are normally gradual and cannot be perceived from moment to moment. Further, the parts are related to one another, enjoying a mutual dependence on and connection with one another. The mind thus tends to neglect the interruptions and to ascribe persistent selfidentity to the aggregate. Now, in the case of the human mind there is a succession of related perceptions. Further, our perceptions are mutually related by means of the causal relation. It is only by memory that we are able to be aware of the causal relations between our perceptions. Hence memory is to be accounted the chief source of the idea of personal identity.
(Source: BPY008/Block 3/Unit 3/Page 33)