whether skepticism about the past requires skepticism about the external world, 3. whether skepticism about the external world requires skepticism about the past, 4. how the arguments for these different skepticisms are related to each other, and 5. my view about these arguments. .
1. To begin with, the view of skepticism must be explained. This view considers that there may or may not be an external world, and if there is, it may or may not be completely different from how it seems to you. Now, skepticism of the past goes something like this: Since all you have to think and believe and remember about exists in your sole mind, how can you be sure about and know about anything in relation to your past experiences and even past existence? Since everything that goes on in your head may or may not be connected to or even existing in the external world, it may or may not be possible that you yourself existed in the past. Skepticism of the past argues the possible idea that perhaps you just came into existence, and your mind was filled with all these memories from the past and present. Unfortunately, you are stuck only with the contents of your own mind to view this problem, and you can't even be sure of that. .
2. Does skepticism about the past require skepticism about the external world? I think the answer to this question is a definite yes. If you are skeptical about whether your past memories and experiences ever existed at all, you certainly have to be skeptical about your own physical existence in the external world. Let's give an example of a boy who is unsure whether he took piano lessons in the past. A way for the boy to find this out could be for him to ask his parents, or call up the supposed piano teacher. He could also sit down at a piano to determine if he has the appropriate skills or not. After all the evidence points towards the fact that the boy indeed did take piano lessons, there is still a level of doubt.