The philosophical branch of epistemology asks a number of crucial questions that all thoughtful people would do well to engage. Epistemology is ultimately the study of knowledge and focuses on questions concerning certainty, how we know what we know, and the nature of knowledge. Below are several commonly employed terms which are helpful starting points for learning more about epistemology and the kind of stuff philosophers write about. This is also an invitation for further research, for nearly all of the below terms are still debated and discussed by philosophers.
Argument – This is a series of statements and reasons an individual uses to convince another person of a conclusion. A valid argument must have premises that are true, hence be sound. Arguments that have invalid premises are viewed as unsound with conclusions that do not follow from the premises.
Abduction – Also referred to as the “inference to the best explanation,” this is a method in logical reasoning in which an individual attempts to find the most likely and/or simplest explanation for an observation.
A Priori & A Posteriori Knowledge – A priori knowledge refers to knowledge (see definition below) that is justified independently of experience, through reason, and that does not depend on experiential evidence or warrant. Alternatively, a posteriori knowledge is knowledge justified through experience, and therefore depends on experiential evidence or warrant. For example, that it is raining outside, that I ate supper an hour ago, and that there is a television in front of me all constitute a posteriori knowledge because it is knowledge that derives from my experience. Alternatively, that I know there is no such thing as a three sided square or married bachelor is considered a priori knowledge. I don’t have to talk to every bachelor in the world in order to know that you don’t get married bachelors.
Axiom – An axiom is a statement that is so well established that it is accepted without question, does not rely on anything else in order to be valid, and cannot be refuted given that any attempt to refute it requires the usage of the axiom in a premise. In other words, they are statements that an individual cannot deny without him using them in his denial.
Belief – Philosopher J.P. Moreland explains that for information or a proposition to become a belief for an individual, the individual must ascribe a certainty of more than 50% to proposition/belief (51% or more). The more certain the individual is of the belief the higher the % ascribed.
Certainty – Although many philosophers once equated certainty with knowledge it has become somewhat standard to separate the two. However, certainty can be understood as not only a property of belief but also the the highest form of knowledge.
Cognitive Faculties – Philosopher Alvin Plantinga explains our cognitive faculties include an individual’s memory, perception, and logical intuition. Plantinga also includes induction which is learning something about the future based on past experience. Most of us assume that these are reliable given that they produce within us true beliefs or at least more true beliefs than false beliefs.
Correspondence Theory of Truth – There are a few theories of truth, however, the most commonly accepted one by philosophers (and almost certainly all of us in general) is known as the Correspondence Theory. This postulates that truth is conformity or correspondence between our thoughts, views, and opinions, and the world. The truth or falsity of a proposition/belief is determined by its relationship to the part of the world described by the proposition/belief. If the proposition/belief does not correspond with a part of the world it describes then it is false, or if it does then it is true. For example, I look at a table on which there is a mug. I form the belief that there is a mug on the table. However, only if there really is a mug on the table can my belief be true.
Deductive Argument – In a deductive argument an individual attempts to establish premises that are so strong that they overwhelmingly support the conclusion to the argument. This is different to an Inductive Argument (see below).
Empiricism – The philosophical view that all knowledge comes from sensory experience.
Epistemology – The lively branch of philosophy that hinges on the question: “How do you know?” There are some 10 or more epistemic theories seeking to provide answers to that question and that lay out what constitutes justified belief and knowledge. Epistemology is ultimately the philosophical study of knowledge.
Epistemological Realism – The philosophical view that what an individual knows about an object exists independently of her mind. This is consistent with the Correspondence Theory of Truth (see above) in that it holds that the world exists independently of our perceptions of it.
Epistemological Subjectivism – The view that knowledge is generated from the individual’s mind and through introspection without reference to the world. These epistemologists hold that the world is a figment of the individual’s imagination.
Fact – This is a thing that is known or has been proven to be true in the sense that it accurately describes the world. A scientific theory, for example, is that which explains and combines a great number of facts about the natural and physical universe. The theory is never proven but a great deal of epistemic warrant is ascribed to it. However, such a definition is contentious to epistemologists. Epistemologists will differ on what it is to “know” something and how one would go about justifying this. Such a question is at the very heart of epistemology itself.
Inductive Argument – In an inductive argument an individual attempts to establish premises that are more likely to be true than not, thus warrant the conclusion as more likely true than not or that are unlikely to be false.
Intuition – This is an individual’s mental state in which a proposition seems true. For example, it is intuitive that a cup cannot be both on a table and not on a table at the same time, or that three sided squares don’t exist.
Justified Belief – There are two major components to justified belief. First, it is the reason as to why an individual holds to the truth of a proposition and/or belief. Second, it is also an individual’s attempt to provide justification of a proposition and/or belief.
Justifiers – Linked to justified belief, justifiers are things that justify a belief or proposition. For example, evidence (forensic, archaeological, textual, or testimonial) counts as a justifier for a proposition and/or belief. Other justifiers also include a priori knowledge, abductive reasoning, deduction, and even divine revelation.
Knowledge – This is an individual or collective group’s awareness and understanding of particular aspects of reality.
Memory – Memory is the way information is encoded, stored and retrieved in an individual. Encoding is taking information from the external world and converting it into mental representations which is then stored in three “locations”: sensory memory (info that is held for a few milliseconds with most info being filtered out), working memory (meaningful info transitions from sensory memory to working memory), and long term memory (info that is deemed really important that can be held for a lifetime). Memory allows an individual to know something that happened in her past.
Perception – This is how an individual knows facts about the world through the use of his or her senses. This includes knowledge about the world derived through the individual’s hearing, seeing, touching, smelling, and tasting capacities.
Proposition – This is a statement, claim, or sentence about the world. For example, “I ate breakfast this morning” and “Lead sinks in water” are claims about the world.
Rationalism – The rationalist is one who argues that knowledge is gained independently of sense experience and emotional response. Rationalists also gain knowledge independently of religious teachings, and often appeal to intellectual and deductive reason as means of gaining knowledge.
Reason – An individual’s ability to apply logic, understand concepts, and make sense of newly obtained information.
Check out my other list of important metaphysical terms we should all know.