Qualitative Identity

Q13. To express that things are identical is to say that they are the same. But there are two meanings of same. (1) being one and the same thing, or (2) being exactly similar, i.e., having all properties in common.
The above is the difference between numerical and qualitative identity. Identical twins are qualitatively identical; they're exactly alike. But they're not merely one and exactly the same thing. On the other hand, I'm numerically identical to the individual I was when I was four. Which means I'm one and exactly the same person. But notice that I'm not qualitatively identical to who I was then.
The idea of identity of time is thus a notion of numerical identity. Plenty of interesting questions are raised once we apply this to people.

Q14. The memory criterion mentioned that A is B if A can remember B's experiences or thoughts. For instance, I can remember being 9, so I'm the exact same person I was when I was nine. But, actually, you can find problems with this memory criterion: it's unlike the transitivity of identity and don't include forward looking psychological connections, such as that between present intention and future action, as determinants of personal identity.
Using example to spell out, the charge that the memory criterion conflicts with the transitivity of identity was illustrated by the famous case of the schoolboy, the young lieutenant and seniors general (Reid 1975). Older people general can Q-remember enough of what happened to the young lieutenant to qualify, by the memory criterion, as being the exact same person while the young lieutenant. The young lieutenant consequently Q-remembers enough of what happened to the young schoolboy. But seniors general can remember next to nothing of what happened to the young schoolboy. Because the memory criterion has it that A Q-remembering enough of what happened to B is a required condition for A being the exact same person as an early on person B, it follows that, in line with the memory criterion, seniors general is not the same person while the young schoolboy. Hence, the

(2) Given our definition, this means that a being than which none greater could be conceived exists in the understanding alone.
(3) But this being could be conceived to exist in reality. That's, we are able to conceive of a circumstance where theism does work, even when we don't believe so it actually obtains.
(4) But it's greater for anything to exist in reality than for this to exist in the understanding alone.
(5) Hence we seem forced to conclude a being than which none greater could be conceived could be conceived to be greater than it is.
(6) But that is absurd.
(7) So (1) should be false. God must exist in reality as well as in the understanding.
This reading of the argument is amply confirmed by the final paragraph, and this is the way he proves that it is true:
“Therefore, if that than which nothing greater could be conceived exists in the understanding alone, the very being than which nothing greater could be conceived is one than which a better can be conceived. But obviously this is impossible. Hence there's undoubtedly that there exists a being than which nothing greater could be conceived, and it exists both in the understanding and in