But at any rate, this is the scientific method of feeling a way out into the unknown, of learning the ways of nature, or of society, or of finance, or of psychology. The knowledge may be empirical, not final, but it is useful to those seeking practical results. The method may be applied in such a field as ethics. If we agree on some fundamental ethical propositions, other ethical propositions can be derived from them, provided that the original premises are stated with sufficient precision. Such ethical premises play a similar role in ethics, to that played by axioms in mathematics.
Truth is what stands the test of experience.
That is to say, if a principle of ethics actually works out beneficially, and does not lead to injustice or other harm, it is true for all practical purposes. And ethics is certainly a practical thing. But the Success Principle is not limited in its application to philosophy and science. It applies in all the affairs of life. In fact that is where its application began.