VCE Philosophy (Year 11) · Unit 1 — Existence and Knowledge · 12m read

Epistemology — Rationalism, Empiricism and Sources of Knowledge

Epistemology asks what knowledge is and how we get it. Do we learn mainly through reason or through the senses?

Learning objective: Compare rationalist and empiricist accounts of knowledge and distinguish a priori from a posteriori knowledge.

By the end of this lesson you can:

• I can define a priori and a posteriori knowledge.
• I can explain rationalism and empiricism with philosophers.
• I can evaluate each view.

Map or exploration?. You can know some things by reasoning (a map’s internal logic) and others only by going and looking (exploring the territory).

Two traditions

A PRIORI — known independently of experience (e.g. 2 + 2 = 4; all bachelors are unmarried).
A POSTERIORI — known through experience (e.g. water boils at 100 °C at sea level).

RATIONALISM (e.g. René Descartes, Gottfried Leibniz)
• Reason is the main source of knowledge; some ideas may be innate.
• Mathematics and logic show we can know necessary truths without experience.

EMPIRICISM (e.g. John Locke, David Hume)
• All ideas come from experience; the mind starts as a "blank slate" (tabula rasa — Locke).
• Hume’s problem of induction: we cannot justify that the future will resemble the past by experience alone.

Immanuel Kant later argued knowledge needs both: "Thoughts without content are empty; intuitions without concepts are blind."

Worked example (Medium)

Classify: (a) A triangle has three sides. (b) The sun rose today. (c) Every event has a cause.

1. (a). True by definition → a priori.
2. (b). Known by observation → a posteriori.
3. (c). Contested — rationalists may see it as known by reason; Hume argued we only observe regular sequences, not necessary causation.

Answer: (a) a priori; (b) a posteriori; (c) disputed between rationalists and empiricists.

Common mistakes

• Saying empiricists reject reason entirely They accept reasoning about ideas but deny it gives knowledge of the world on its own. Fix: Be precise about the claim.
• Mixing up a priori and a posteriori Latin terms are easy to swap. Fix: Prior = before experience; posterior = after experience.

Practice questions

1. Who described the mind at birth as a "blank slate"?

   1. Descartes
   2. Locke
   3. Leibniz
   4. Plato

   (1 marks)

2. Explain Hume’s problem of induction.

   (3 marks)

Summary

• A priori vs a posteriori.
• Rationalism: reason; empiricism: experience.
• Hume’s problem of induction.
• Kant combined both.