Epistemology

Knowledge is a type of belief, and epistemology is the study of knowledge, that is, the analysis of how we know the world, as opposed to ontology, which deals with what we take to be real. An epistemology is a worldview with a particular set of assumptions, a definition of truth, and priorities concerning what constitutes valid and important knowledge. Knowledge comprises those beliefs that are both true (they conform to what is real) and justified (the one who thinks them true has sufficient reason to think them true). This formulation attempts to formally distinguish the type of belief we call knowledge from other types of belief, such as errors (untrue beliefs) and lucky guesses (true beliefs held without justification).

Everyone has an epistemology, whether they know it or not. In academic analysis, epistemologies are made explicit as they underlie the rules of knowledge formation. Different epistemologies have different criteria for what constitutes valid knowledge, different definitions of truth, and different priorities in terms of how analysis should be done. Each piece of knowledge can be considered a proposition. Propositions can be sorted (not without remainder) into three epistemic classes: demonstrable propositions (those that can be shown to be true by appeal to logic or fact), defensible propositions (those for which a convincing rational argument can be made), and preferred propositions (those that reflect individual subjective taste and cannot or need not be defended). We hope to win another person's assent to a demonstrable proposition when we can “show” them it is true in a manner that all rational humans will find persuasive. The truth of such statements is given either a posteriori, or as empirically evident to the senses (e.g., “Water runs downhill”), or a priori, that is, by definition and logical deduction (e.g., “A man cannot marry his own widow”).

Other propositions may not be clearly demonstrable on empirical or logical grounds, but arguments can be offered in their favor. Dispute over defensible propositions results in agreement only some of the time. This is because their truth or falsehood cannot be conclusively demonstrated beyond the shadow of reasonable doubt. Disputants can only advance arguments for and against such propositions. Assent (or dissent) follows a judgment, or weighing, of arguments, reasons, and considerations, but unanimity may not be attained. An example of such a proposition is “The death penalty is unjust.” Each person believes that the judgment with which she or he responds to a question such as “Is the death penalty justified?” is true and justified but, in the course of dispute with those with a different answer, finds that his or her judgment is, at best, defensible and cannot be “proven” empirically or logically. No one person's argument can carry the day, for other people's judgments are defensible too.

Last, some propositions state preferences that are simply subjective expressions of individual taste. “Wensleydale is the finest cheese” or “Fall is the finest season” are propositions of this sort. In asserting them, people have no empirical evidence or inescapable logic to advance in their favor. Because they simply express a preference, they require no defense. No one knows what I like better than I, thus the famous adage: de gustibus non est disputandum (“There is no disputing taste”).

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