What is knowledge and how do we obtain it?

Christopher L. Holland
christopher.holland@slu.edu

Saint Louis University

February 18, 2025

Knowledge and its Types

  • Knowledge by Acquaintance
  • Competence Knowledge
  • Propositional Knowledge

Knowledge by Acquaintance

A person \(S\) knows something or someone \(x\) (where \(x\) is the direct object of the sentence).

Examples:

  • I know my friend David.
  • I know I have a headache.
  • I know I seem to be seeing a window over there. Knowledge by acquaintance includes introspective states, objectual knowledge, and perceptual knowledge.

Competence Knowledge

Sometimes called “skill knowledge” or “know how”.
A person \(S\) knows how to \(D\) (where \(D\) stands for an infinitive).

Examples:

  • I know how to ride a bike.
  • I know how to speak English.
  • I know how to play the piano.

Competence Knowledge

  • involves the ability to perform a skill.
  • can be conscious knowledge or unconscious knowledge.

Note: You don’t have to be able to explain your own know how to have know how.

Propositional Knowledge

Also called “descriptive knowledge”
A person \(S\) knows that \(p\) (where \(p\) is some statement or proposition).

Examples:

  • I know that \(2+2=4\).
  • I know that the sun will rise tomorrow.
  • I know that this class meets at 8:00 a.m. Tues. and Thurs.

Many philosophers believe that only reflective beings, such as human beings and perhaps some adult primates and cetaceans (like dolphins and porpoises) have propositional knowledge.

What is Knowledge?

Can you know something that is really false?

  • The people in the Middle Ages knew that the earth was flat, but they were wrong.
  • I know that the US Declaration of Independence was signed in 1945, but it was not.

Classic Definition of Knowledge:

  • Justified true belief
  • Each element is necessary for knowledge, but no one element is sufficient on its own.

What is a Belief?

  • Belief: A propositional attitude of truth
  • Occurrent Belief: a belief that you are conscious of at the moment
  • Dispositional Belief: a belief that you may or may not be conscious of at the moment, but that you would become conscious of under suitable conditions

What is Truth?

Classic definition from Aristotle:

  • Falsehood: “To say of what is that it is not, or of what is not that it is, is false.”
  • Truth: “To say of what is that it is, and of what is not that it is not, is true.”

Correspondence Theory of Truth

  • Truth is a relationship held between a proposition and reality.
  • A proposition is true if, and only if, it corresponds to reality.
  • A proposition is false if, and only if, it does not correspond to reality.
  • The correspondence theory is a metaphysical theory of truth.

Coherence Theory of Truth

  • Truth is a relationship held between propositions and other propositions.
  • A proposition is true if, and only if, it coheres with a particular set of propositions.
  • The coherence theory is an epistemological theory of truth.

What is Justification?

  • Evidence or support for a belief
  • But what counts? And how much is needed?
  • Do I have to know that I know?

Types of Propositional Knowledge

  • Epistemological Categories
    • A priori: Knowledge that does not depend on evidence from sense experience.
    • A posteriori: Contingent, empirical knowledge that does depend on evidence from sense experience.
  • Semantic Categories
    • Analytic: The predicate is contained in the subject (e.g., “All mothers are women”)
    • Synthetic: The predicate is not contained in the subject but adds something to the subject (e.g., “Mary is a mother”)

How Do We Obtain Knowledge?

  • Rationalism
  • Empiricism

Rationalism

  • Key figures: René Descartes, Baruch Spinoza, Gottfried Wilhelm Leibniz
  • Rationalists believe that reason is sufficient to discover truth.
  • Rationalists believe in innate ideas (or at least something similar).

Empiricism

  • Key figures: John Locke, David Hume, George Berkeley.
  • Empiricists believe that all nonanalyic knowledge originates through sense perception.
  • All knowledge of the world is a posteriori knowledge. Only knowledge of logic and mathematics is analytic and a priori.
  • Rejects innate ideas.

Locke on Innate Ideas

  • Tabula Rasa (blank slate)
  • Locke rejects innate ideas because:
    1. No good deductive argument establishes the existence of such entities
    2. Children and people with sever cognitive disabilities do not seem to possess them
    3. An empirical way of knowing, which seems far more reasonable, has no place for such entities

Sources

  • DeWeese, Garret J. and J. P. Moreland. Philosophy Made Slightly Less Difficult. Downers Grove: InterVarsity Press, 2005.
  • Moreland, J. P. and William Lane Craig. Philosophical Foundations for A Christian World View. Downers Grove: InterVarsity Press, 2003.
  • Pojman, Louis. Philosophy: The Pursuit of Wisdom. 5th ed. Boston: Wadsworth, 2006.
  • Pojman, Louis and Lewis Vaughn. Philosophy: The Quest for Truth. 10th ed. Oxford University Press, 2017.
DeWeese, Garrett J., and James Porter Moreland. 2005. Philosophy Made Slightly Less Difficult: A Beginner’s Guide to Life’s Big Questions. Downers Grove, Ill: InterVarsity Press.
Moreland, J. P., and William Lane Craig. 2017. Philosophical Foundations for a Christian Worldview. 2nd Edition. Downers Grove, Illinois: IVP Academic.
Pojman, Louis P. 2006. Philosophy: The Pursuit of Wisdom. 5th ed. Belmont, CA: Wadsworth.
Pojman, Louis P., and Lewis Vaughn, eds. 2017. Philosophy: The Quest for Truth. 10th ed. New York: Oxford University Press.