(BTW, I am not advocating swallowing the following paradigm whole -- I may blog on it in the future if the muses hit me -- but I do think these premises are important to be aware of.)
1. Existence. There exists a physical world separate and distinct from our minds that is comprehensible through our senses. We expect in addition that it is governed by certain generalities called the “laws of nature.”
2. Causality. Events—effects—in the physical universe have natural causes. Causes precede effects and can be explained rationally in terms of the laws of nature.
3. Position symmetry. The laws of nature are the same everywhere in the universe.
4. Time symmetry. The laws of nature have remained the same through time. They are the same now as they were in the distant past, and they will be the same in the future.
5. Noncontradiction. Of two contradictory propositions, both cannot be true.
6. Simplicity (Occam’s Razor). If alternative explanations of any phenomenon are available, where each are logical and explain the phenomenon equally well, then the simplest explanation shall be chosen.
From: Physical Science Foundations, 2nd ed., BYU College of Physical & Mathematical Sciences.
I found these six premises on this gentleman's blog, and thought it would be an important piece of knowledge and understanding here as well.