Two comments.
You don't have to believe that PR works. HOWEVER, you can't believe it doesn't work. If you have dislief in the viability of something like PR it will hinder your learning it. If you have doubts, then your learning will be impeded. If you mistrust the validity of the PR, then you will not accept and use the teaching of the PRWMS as easily and completely as you a capable.
If it NOT necessary to believe it works. The course asks you to approach the material with and open mind. To use the material with the mind of a beginner, the mind of one seeking not judging.
It is not necessary for you to do this. However, you may have to use the PRWMS a lot longer before you see results if you don't. You don't have to believe it works. However, if you truly approach it with an open mind you will proceed more quickly and smoothly.
If you are doubtful, you can consciously learn all the material, but you are not just dealing with the conscious mind.
Hear and I foget.
See and I remember.
Do and I understand.
People on the forum usually say you have to believe in the system, because that is the easiest way to convey the necessary concept for learning PRWMS. If we used a negative affirmation like "You can't disbelieve that PRWMS works", then as NLP says we would not be helping you. We must be positive. LSC doesn't preach belief in their system. They merely ask you to adopt an open mind when learning and using the system. They leave the choice up to you. So what is your choice?
The second comment is on what is proof?
I studied as a physicist, but I took many math courses from the mathematics department. More than one proof, from upper year math courses, were sent back by a TA saying "this is not a proof". I knew full well that were very acceptable in a physic-math course. So I went out and read up on proofs; even buying a book on proofs. The gist of it is that a proof is an argument that convinces someone of an ascertion. The argument won't convince everyone. If you thing that physical so-called facts will convince people, you should think again. Many people will deny conclusions you or others would accept. You will deny conclusions that others will accept.
I am reminded of a second year differential equations course. We learned to use the Big D operator. If was developed by an engineer; Oliver Heavyside I believe. I made many problems trivial to solve. However, a large portion of the mathematical community dismissed it as invalid because they could not find a mathematical foundation for it. They could not prove it should work. I believe it was over a hundred years before someone discouvered that the Big D operator was a Laplacien transform. Then of course it was more widely accepted.
You can wait until someone comes up with an argument or evidence that will convince you, or you can try and follow the instructions in the PRWMS as best you can and see what happens. I would suggest you revisit the material several times, irregardless of whether you get results on the first time through. There will be material you didn't fully appreciate or use during the first pass.
You are perfection.
Iam2 
