**Abstracts:** The Standard Model seems to explain nature precisely. However, a fundamental revision is appropriate because neither the accepted assumption of classical physics, the equivalence of inertial mass and gravitational mass, nor the used quantum conditions of microscopic physics appear as valid hypotheses. The fundamental field of nature (UF) consisting of the electromagnetic field and the covariant gravitational field is generated by four types of sources. Each source = quantum of the field, represented through the four stable particles e, p, P and E, has two invariant Maxwell charges. The source quantization leads to variation principles of open physical systems in finite space-time domains and discovers beside the Planck’s constant h a second basic constant *h ^{0}= 1/4 ⋅ √2^{ }⋅ q²/c * which is responsible for the neutrinos as bound states. The centralization of the UF and of the four stable particles in physics is resulting in an investigation of two sets of hypotheses, the set of historical gathered assumptions and a set of new fundamental hypotheses which leads to Principles of Physics.

PACS Numbers: 03.70.+k, 04.20.Cv, 12.10.-g, 13.15.+g