Schick and Vaughn Chapter 5

Knowledge, Belief, and Evidence

Propositional knowledge is “knowledge that ...”. It is opposed to “knowledge how”.

Plato’s view: to know p (a proposition) requires that

  1. p is true (corresponds to how things are).

  2. I believe p.

  3. I can give reasons (justify) my belief that p.

Plato’s dialog Theatetus – which you are welcome to read – explains this view in detail.

Knowledge, then, is justified true belief.

Knowledge and Certainty

Some people (e.g., the philosopher Descartes) say we can’t know p unless we’re absolutely certain that p.

Does knowledge require absolute certainty? No. We all believe things we’re not absolutely certain of (e.g., that the sun will rise tomorrow, that we have bodies, etc.). But we have very good reasons to believe the sun will rise tomorrow and that we have bodies. Those reasons are sufficient to say we know the sun will rise tomorrow, for all practical purposes. If we ever encounter good reasons to doubt that the sun will rise tomorrow (say we discover that earth might be knocked out of orbit in the near future by an asteroid), then we can say we don’t know. But as long as we have no good reasons to doubt that the sun will rise tomorrow, we can say we know it. We can say we know p if we have good reasons for believing p.

Radical philosophical skepticism (the view that we can’t really know anything) is unreasonable (because we do seem to know some things), self-contradictory (because the skeptic claims to know that he cannot know), and vacuous (because we cannot help but behave as though we know some things).

So the next interesting question is: what are good reasons? What makes p a justified belief?

What counts as justified belief?

Belief that p is not justified if we have good reason to doubt p.

Thus (by contraposition) belief that p is justified if we have no good reason to doubt p.

Rule (98): “We are justified in believing a proposition when we have no good reason to doubt it.”

We also say belief that p is justified if p is the best explanation for the observed phenomena.

If belief is justified, it’s okay to say p is “true beyond reasonable doubt.

Of course, skeptics are right that beliefs true beyond reasonable doubt might still be false.

But in most contexts, “true beyond reasonable doubt” is sufficient for claiming knowledge.

Good reasons to doubt p (i.e., to make p less reasonable to believe)

  1. We should doubt if p conflicts with (is inconsistent with) the rest of our reasonable beliefs.

    Rule (99): “There is good reason to doubt a proposition if it conflicts with other propositions we have good reason to believe.”

  2. We should doubt if p conflicts with (is inconsistent with) our background information – our general world knowledge.

    Rule (100): “The more background knowledge a proposition conflicts with, the more reason there is to doubt it.”

  3. We should doubt if p conflicts with genuine expert opinion.

Insufficient reasons to believe, other things being equal:

Coherence of p with our other beliefs is not sufficient to establish p.

(NOTE: Conflict – incoherence – with other beliefs is prima facie reason to doubt p; but coherence is not prima facie reason to believe p.)

Ideologies (for example, Marxism, Freudianism, Christianity) are completely coherent; everything fits together and every phenomenon can be explained. But the whole self-contained system might be wrong, since these systems are consistent with all states of affairs.

Good reasons to believe, other things being equal:

Senses, memory, introspection.

But remember Chapter 3: other things are not always equal.

Is faith ever a source of knowledge?

Faith is precisely unjustified belief. If knowledge is justified belief, faith cannot be a source of knowledge.

James’ precursive faith: e.g., believing that someone likes you (in order to bring it about), or the stranded mountain climber example.

James says these cases show that precursive faith can be rational (true); but according to SV, James is wrong to say these cases are faith, as defined above. Both cases “are based on well-known facts about human behavior.” (111)

Sidebar p. 112: Richard Dawkins argues that faith (construed as a source of knowledge) is a “mind virus.”

Is “intuition” ever a source of knowledge?

What do we mean by “intuition”? ESP? HSP?

There is no good reason to believe in extra-sensory perception (ESP).

But what about hyper-sensory perception (HSP), as “evidenced” by Sherlock Holmes, Counselor Troi, Clever Hans, Ilga K (115)? Yes! HSP is well-established, e.g., by Rosenthal’s experiments (114). But it’s not ESP.

Is “mystical experience” ever a source of knowledge?

Capra and LeShan say mystical experience is a “privileged road” to knowledge.

Capra in his famous book The Tao of Physics argues that modern physics and Eastern mysticism, surprisingly, are in perfect agreement about the ultimate nature of reality. At the largest and smallest levels of being, all distinctions disappear, logic becomes useless, self and non-self merge, temporal distinctions melt away, and everything is connected to everything else (“everything is one”).

An interesting idea, no?

What do we mean by mystical experience? “Mystical experiences are ecstatic, awesome, extraordinary experiences in which you seem to enter into a mysterious union with the source and ground of being.” (117)

In mystical experience, you are supposed to gain a new understanding of the universe and your place in it. Typically, the mystic claims to experience ecstatic unity with a magnificent indescribable and benevolent reality.

Some mystics claim that the self merges with this reality and disappears; others claim the self persists, as in a sexual union. Buddhists claim there’s no self to begin with. There seems to be a variety of mystical experiences. Christian mystics experience union with Christian figures; Hindu mystics with Brahman, or lesser gods, etc.

Problems: “ineffability” (if mystical experiences are really ineffable – indescribable – there’s no way to tell if mystics are all having similar experiences at all); cultural dependence; possible alternative psychological interpretations (sensory deprivation, sexual fantasy, etc.)

But showing that mystical experiences have physiological causes doesn’t say anything one way or the other about whether the mystics’ claims are true or reasonable to believe, or “good myth.”