5: Limiting Knowledge



Key Terms

Analytic Truths
Synthetic Truths
Hume's Fork
Transcendental Idealism

  • Read and analyze a description of philosophical thought
  • Articulate key conceptual distinctions between rationalism and empiricism
  • Articulate key conceptual distinctions between noumenal and phenomenal and analytic and synthetic truths
  • Demonstrate knowledge of Hume’s Skepticism, Hume’s Fork, and Kantian Transcendental Idealism.

I. Hume & Kant in Brief

  • A. Hume
    • Skepticism
    • Anything we cannot experience is unknowable
  • B. Kant
    • Transcendental Idealism
    • Attempt to reconcile empiricism and rationalism
    • Synthetic vs. Analytic Truths

II. Hume

  • A. Skepticism
    • Doubting all assumptions (Descartes)
    • Claiming no knowledge is possible under any circumstances
    • Radical view based on empiricism
    • Hume applies skepticism to everything
      • Science
      • Other philosophical arguments
      • The principle of universal causation and the principle of induction
  • B. Contents of the Mind
    • Impressions - actual experiences
      • Tasting an apple
      • Immediate feelings of pain, hunger, etc.
    • Ideas - copies of impressions
      • Memory of the apple's taste
      • Remembering pain, hunger, etc.
  • C. Hume’s Fork: Relations of Ideas
    • Discoverable by reason
      • Facts we don't traditionally question
      • Opposite of the idea would not be true
      • Hume claims these are not true knowledge

Relations of Ideas

  • All triangles have three sides.
  • All bachelors are unmarried
  • A2+B2=C2
  • D. Hume’s Fork: Matters of Fact
    • Proven by experience
      • Because these are based on experience, they are true knowledge

Matters of Fact

  • All bachelors are messy.
  • All dogs have four legs.
  • Apples are red.

  • E. Truth in Relations of Ideas and Matters of Fact
    • Because Relations of Ideas do not require experience and are discovered through reason, they are impossible
    • Only Matters of Fact are true knowledge because they require experience

III. Kant

Immanuel Kant

  • A. Transcendental Idealism
    • Theory in response to the debate about rationalism and empiricism
    • Counters Hume's Skepticism
    • We can have true knowledge through both reason and experience
    • Pure a priori knowledge is possible because knowledge can come without direct experience
  • B. Analytic vs. Synthetic Truths
    • Analytic Truth - true by virtue of the meaning of the words
      • All bachelors are unmarried males.
      • Do not add to our knowledge
      • Based on reason, not experience
    • Synthetic Truth - true based on our experiences
      • Add to our knowledge
      • Based on knowledge synthesized from experience
    • This approach justifies and reconciles rationalism and empiricism
  • C. Kantian Metaphysics
    • We see the world in two ways: phenomena and noumena
    • Phenomenal world
      • What we see, touch, etc. 
      • How we experience the world as constructed by the mind
    • Noumenal World
      • The way the world is in itself, when no one is looking at it. 
      • The world beyond our perception
      • We cannot know the noumenal world
    • The mind takes in raw unorganized noumena and organizes it into phenomena (our experiences)
    • The mind, therefore, has both components, sensing and understanding

Logic Week 5: Reductionist Fallacy