Axiology: philosophy of values, of their nature and of value judgments.
From the Greek, axioma, “what is thought to be worthy”, the ultimate, but under-theorized category of value reason, ideally building from rationally self-evident bases or axioms of value a complete system of value (aesthetic, epistemological, moral, etc.) with unlimited validity across domains. Onto-axiology is axiology which grounds in the nature of being.
From the Greek, axioma, “what is thought to be worthy”, bridging from rationally self-evident bases or axioms of mathematics and logic (deciding correct sequences) to ultimately regulating principles of value and value-systems as organizing frameworks of pro-con choices of good and bad at individual and social levels, seeking unlimited validity of explanation.
Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11.