I also hope you will get used to asking yourself the question "How do I know...?" Is it because the book / table says so? Because someone you trust told you? Because you have seen it with your own eyes? Because you can follow the mathematics / arguments leading to this conclusion? Or you just know? Obviously, we cannot question everything in life - we have to find a balance between "critique" and "accept" and sometimes apply a "provisional accept". This balance is something that everyone has to work out for themselves, develop and refine over the years and I think that your own balance will be reflected in your project work.
You may also want to think about the relation between science and our view of the world, see e.g. what von Wright writes about the "Crisis of Intelligibility"
On separate pages, I try to specify in more detail how I expect you to work and what I expect you to achieve in the different parts of the course. See also the FAQ list.