This handout is a supplement to the Handout III, "To Know or Not to Know, That is the Question!" Case references below refer to cases described on that handout.

1. Three Kinds of Knowledge

The word "knowledge" is used in three distinct ways in contemporary, ordinary language.

Practical or Know How Knowledge (e.g., Johnny knows how to ride a bicycle)

Object or Acquaintance Knowledge (e.g., Monica knows Bill Clinton)

Propositional Knowledge (e.g., Lisa knows that it is raining outside).

Notice in the examples that each statement about so and so knowing "something" differs in structure from the others. The difference is exemplified by the different object the verb "knows" takes in each sentence. In practical knowledge, the object of "knows" is an ability to perform some kind of action. In acquaintance knowledge, the object of "knows" is a thing, person, or place, an object of some sort. In propositional knowledge, the object of "knows" is a proposition, the meaning expressed by a declarative sentence.

Epistemology is primarily concerned with propositional knowledge. More precisely, epistemology is concerned with analyzing the concept of propositional knowledge, not the English word "knowledge" but the concept this word denotes (and that many other words in other languages also denote). Philosophical inquiry in general is often concerned with analyzing concepts (e.g., God, reality, justice, goodness, death). Since "concepts" are universals (which have instances), the central goal of epistemology is to determine what people have in common when they know some proposition.

A widely accepted view of knowledge, originating perhaps opaquely in Plato, is the tripartite view of knowledge (i.e., knowledge requires three conditions).

Let S = equal some cognizer, and p = some proposition.

S knows that p if and only if

1. S believes p. (doxastic condition)
2. P is true. (alethic condition)
3. S is justified in believing p. (justification condition)

3. Belief and Truth

A. Belief

"Belief", as it is being used in this context, simply indicates an attitude toward a proposition. Call this a propositional attitude. There are three such attitudes that can, in principle, be taken.

• Believe that p (take p to be true)
• Disbelieve that p (take p to be false)
• Suspend judgment or withhold belief that p (neither believe p nor disbelieve p)

(1) Beliefs are held with different degrees of conviction, from weak belief to psychological certainty. (2) The belief condition required for knowledge requires something in between weak belief and psychological certainty, something like "firm conviction." (3) Holding some belief does not entail that the belief is true, for some beliefs are false.

B. Theories of Truth

• Correspondence Theory: The belief that p is true if and only if it corresponds with the fact that p.
• Verificationist Theory: The belief that p is true if and only if it is an instance of (idealized) acceptable rationality.
• Pragmatic Theory: The belief that p is true if and only if it is useful.

(1) (A) is a realist theory of truth, as the fact that makes a belief true is objective or independent of the minds of human persons in some way. (B) and (C) represent anti-realist theories of truth, since they each imply that a belief's being true depends in some way on the existence of human persons, e.g., their conceptual schemes, community standards, or practical goals. (2) The so-called coherence theory of truth is related to verificationism. For instance, if coherence represents idealized rationality, then verificationism and coherentism are the same.

3. Justification Theories

What is required to be justified in believing p? Justification relates in an important way to the truth goal of believing. Roughly put, a justified belief is a belief that accompanies or has some indication of being true (e.g., evidence, reasons, grounds - where these are understood as truth indicators). So we can think of the justification condition as a positive link between the doxastic and alethic conditions of knowledge. Justification places a person is a good or strong position with respect to the truth goal of believing. In this way, it is similar to epistemic rationality. In fact, some take justification to simply be some form of epistemic rationality, e.g. internal or deontological rationality.

But there are different ways of understanding the idea of a truth indicator or being in a good position vis-à-vis the truth goal of believing. These lead to different ways of specifying what is required for justification.

1. Evidential Justification: S is justified is justified in believing p if and only if the belief that p is based on good evidence, grounds, or reasons. This is a very common way to construe justification, but there are different senses of "evidence" that must be distinguished.

• Evidence narrowly construed can be taken as merely propositional evidence (i.e., other beliefs or propositions). (See coherentism below)
• Evidence more broadly understood can include "experiential" evidence as well as other beliefs (e.g., the evidence of your senses, memory, and introspective experience).

1. Deontological Justification: S is justified in believing p if and only if S is not in violation of any relevant epistemic obligations in believing p. "Justification" here is equivalent to the idea of deontological rationality (discussed on Handout II). Deontologism is often combined with evidential justification; for instance when it is held that one has a duty to believe only on the basis of good evidence.
2. Reliabilism: S is justified in believing p if and only if S's belief that p was produced by a reliable process of belief formation OR is based on a ground that produces a statistically high number of true beliefs. This view is often combined with or explained in terms of a causal theory of justification, according to which one knows that p only if one's belief that p was caused by the fact indicated by p.
3. Proper Function: S is justified in believing p only if S's belief that p was produced by properly functioning, truth-aimed cognitive faculties. I say "only if" here because proper function theories usually require something more than just proper function, such as reliability and being in the right sort of cognitive environment. See Handout II for more on proper function.

Theories (A)-(D) are typically divided into internalist and externalist theories. An internalist theory of justification maintains that what justifies a belief is a mentally accessible item, something that the person can come to know whether it obtains just by reflecting one one's mental states. One beliefs and experiences are internal in this sense. Hence, (A) and (B) are species of internalism. Externalism is simply a denial of internalism. What confers justification on a belief is not a mentally accessible item. Since reliability of belief formation and proper function are not cognitively accessible items, (C) and (D) are externalist theories. Externalist theories often use the word "warrant" instead of justification on the grounds that "justification" is a word with internalist connotations. I will continue to use the word "justification."

For a critique of (A) and (B), see my on-line paper "Evidential Justification and Deontologism."

5. The Gettier Problem

The tripartite view of knowledge is has its detractors though. Edmund Gettier challenged the tripartite view of knowledge in his paper "Is Justified True Belief Knowledge?" (Analyses, 1963). The article includes a case of a person inferring a true belief B from a false one, but where it appears that a person is justified in holding B, and yet it seems as if the person does not know B (see case #6, Handout III). Of course, to escape this problem, we need only modify the notion of justification to require "no dependency or inference from a false belief." But Gettier type cases can be generated that do not include dependency on a false belief, as when we move directly from a perceptual experience to a particular belief (see cases #2 and #4). So the requirement that there be "no dependency or inference from a false belief" will not address all Gettier type cases.

What is the common character of Gettier cases?

The common characteristic of all Gettier Cases is that they involve epistemic luck. That is to say, they involve cases of people getting a true belief by accident. Owing to the widely shared intuition that knowledge is not compatible with epistemic luck, either justification must rule out accidentally true belief or the tripartite view of knowledge is incorrect (i.e., there must be a forth condition of knowledge). But not just any kind of epistemic luck is at issue.

There are two kinds of epistemic luck.

• Veridic epistemic luck, according to which it is an epistemic accident that a person holds a true belief. S believes p, but S is just lucky that it turns out that p is true. (See cases #2-#6)
• Evidential epistemic luck, according to which it is no accident that S's belief is true given the evidence S has, but it is a matter of luck that S has the evidence he does. (see case #13; #12 is controversial)

Hence, it seems that knowledge must be a true belief that does not depend on veridic epistemic luck. How does this affect the tripartite view of knowledge? Either justification must exclude this possibility or the tripartite view of knowledge is incorrect, or at least incomplete. Some add a fourth condition to deal with Gettier type cases. Also some argue that no internalist theory of justification can escape veridic epistemic luck. Hence, a reason for favorably considering externalist theories.

6. Knowledge and Internalist Defeaters

It also seems that knowing p must exclude a person's having sufficient reasons for supposing either that p is false or that the belief that p is not grounded or produced in a way that is sufficiently truth-indicating. (See Handout III, cases #9 and #10; contrast with case #11). Such conditions may be called internalist defeaters. They are conditions that, if they obtain, would defeat positive epistemic status, but they are distinctly internal conditions since the reasons that produce defeat in such cases are either other beliefs or experiences of the person. This was introduced on Handout II, with reference to rational belief.

We can call this negative constraint, the no-defeater condition: S knows that p only if S does not have a sufficient (internal) reason for supposing either that p is false (a rebutting defeater) or that the belief that p is inadequately grounded (an undercutting defeater).

The no-defeater condition may be worked into the definition either by making it a fourth condition for knowledge (independent of justification), or - more plausibly - by making the no-defeater condition a necessary condition for justification (itself necessary for knowledge). Moreover, even an epistemic externalist (who thinks that justification or knowledge is conferred by something external to the subject) can advocate this negative internalist constraint. There is no straightforward inconsistency in affirming that what confers justification on a belief is an external condition, but what takes justification away from a belief is an internal condition.

Hence, we may summarize knowledge as follows:

1. Foundationalism: The epistemological view that, though some beliefs are justified by virtue of their evidential dependence on other justified beliefs (non-basic beliefs), there are some beliefs that are justified by virtue of something other than their evidential dependence on other justified beliefs (basic beliefs).

• Ancient Foundationalism: (a) Properly basic beliefs are either self-evident or evident to the senses. (b) The evidential relation between beliefs is typically deductive. (e.g., Aristotle)
• Modern Foundationalism: (a) Properly basic beliefs are either self-evident or about one's own immediate states of consciousness. (Locke may be an exception here, as he seems in places to include evident to the sense). Hence, properly basic beliefs are immune from various epistemic liabilities (liability to error, doubt, or revision). (b) The evidential relation between beliefs is deductive (e.g., Descartes) or probabilistic (e.g., John Locke).
• Non-Classical Foundationalism: (a) Properly basic beliefs are not limited to the class represented by either ancient or modern foundationalism. (b) The evidential relation between beliefs includes probabilistic relations. (e.g., Locke). Although non-classical foundationalism has been a largely 20^th century development, the 18^th century common sense philosopher, Thomas Reid, anticipates it.

(1) Foundationalism is logically consistent with most internalist and all externalist theories of knowledge. (2) In Non-Classical Foundationalism, what gets placed in the class of properly basic beliefs depends largely on other features of one's epistemology. For instance, for the reliabilist it will be sufficient for proper basicality that a belief is produced by a reliable non-inferential belief forming process (e.g., sense experience, memory, etc). (3) In Non-Classical Foundationalism, both properly basic beliefs and non-basic beliefs can be defeated. (4) The same belief might be properly basic for one person and properly non-basic for another, especially in non-Classical Foundationalism, as the structure of belief is relative to individual persons.

B. Coherentism: The epistemological view that all justified beliefs receive their justification by virtue of evidential relations with other justified beliefs.

• Linear Coherentism: The evidential relation between beliefs I spelled out in terms of specific inferential patterns (such as deductive or probabilistic connections) between individual beliefs.
• Holistic Coherentism: The evidential relation between beliefs is spelled out in terms of the whole set or network or beliefs. A given belief is justified by fitting in (in some sense) with the whole set of other beliefs.

More Thoughts on Coherentism:

(1) Coherence theories are internalist theories (though not all internalist theories are coherence theories, as noted above). (2) It is important to distinguish between coherence theories of justification and coherence theories of truth. The former, which is under consideration here, says that coherence with other beliefs is what makes a particular belief justified. The latter says that coherence with other beliefs is what makes a particular belief true. But truth is not the same thing as justification. (3) I have assumed above what are called positive coherence theories. There are also negative coherence theories, according to which lack of coherence with some other beliefs defeats justification or knowledge. This may overlap with internalist defeaters. (4) Coherence theories are consistent with internalism, but ordinarily inconsistent with externalism, the primary exception being negative coherence theories.