The fact–value distinction is a fundamental epistemological distinction described between: 'Statements of fact' ('positive' or 'descriptive statements'), based upon reason and physical observation, and which are examined via the empirical method. 'Statements of value' ('normative' or 'prescriptive statements'), which encompass ethics and aesthetics, and are studied via axiology. This barrier between 'fact' and 'value' implies it is impossible to derive ethical claims from factual arguments, or to defend the former using the latter. The fact–value distinction is closely related to, and derived from, the is–ought problem in moral philosophy, characterized by David Hume. The terms are often used interchangeably, though philosophical discourse concerning the is–ought problem does not usually encompass aesthetics. Religion and science In his essay Science as a Vocation (1917) Max Weber draws a distinction between facts and values. He argues that facts can be determined through the methods of a value-free, objective social science, while values are derived through culture and religion, the truth of which cannot be known through science. He writes, "it is one thing to state facts, to determine mathematical or logical relations or the internal structure of cultural values, while it is another thing to answer questions of the value of culture and its individual contents and the question of how one should act in the cultural community and in political associations. These are quite heterogeneous problems." In his 1919 essay Politics as a Vocation, he argues that facts, like actions, do not in themselves contain any intrinsic meaning or power: "any ethic in the world could establish substantially identical commandments applicable to all relationships." To MLK Jr., "Science deals mainly with facts; religion deals mainly with values. The two are not rivals. They are complementary." He stated that science keeps religion from"crippling irrationalism and paralyzing obscurantism" whereas Religion prevents science from "falling into ... obsolete materialism and moral nihilism." Albert Einstein remarked that David Hume's skepticism In A Treatise of Human Nature (1739), David Hume discusses the problems in grounding normative statements in positive statements, that is in deriving ought from is. It is generally regarded that Hume considered such derivations untenable, and his 'is–ought' problem is considered a principal question of moral philosophy. Hume shared a political viewpoint with early Enlightenment philosophers such as Thomas Hobbes (1588–1679) and John Locke (1632–1704). Specifically, Hume, at least to some extent, argued that religious and national hostilities that divided European society were based on