But having once acquired this notion of causation from the memory, we can extend the same chain of causes, and consequently the identity of car persons beyond our memory, and can comprehend times, and circumstances, and actions, which we have entirely forgot, but suppose in general to have existed.

For how few of our past actions are there, of which we have any memory?
Who can tell me, for instance, what were his thoughts and actions on the 1st of January 1715, the 11th of March 1719, and the 3rd of August 1733?
Or will he affirm, because he has entirely forgot the incidents of these days, that the present self is not the same person with the self of that time; and by that means overturn all the most established notions of personal identity?
In this view, therefore, memory does not so much produce as discover personal identity, by shewing us the relation of cause and effect among our different perceptions.

It will be incumbent on those, who affirm that memory produces entirely our personal identity, to give a reason why we cm thus extend our identity beyond our memory.
The whole of this doctrine leads us to a conclusion, which is of great importance in the present affair, viz.

that all the nice and subtile questions concerning personal identity can never possibly be decided, and are to be regarded rather as gramatical than as philosophical difficulties.

Identity depends on the relations of ideas; and these relations produce identity, by means of that easy transition they occasion.