Rationalism Lecture Review

Rationalism

Introduction

• Rationalism is a major philosophical tradition emphasizing reason as the primary source of knowledge.
• It contrasts with empiricism, which prioritizes sensory experience.
• Rationalists like Descartes, Spinoza, and Leibniz argue that certain truths are known independently of observation.
• These truths are discovered through logical deduction and innate ideas.

Core Principles of Rationalism

• Reason Over Sensory Experience: The mind uses logic and deduction to discover truths.
  • Example: Mathematical truths (2 + 2 = 4) are known by reason, not sensory input.
• Innate Knowledge: Some ideas are hardwired into the mind at birth.
  • Examples include the concepts of God, morality, and geometric axioms.
  • This contrasts with Locke’s tabula rasa (blank slate) empiricism.
• Deductive Certainty: Rationalists prefer deductive reasoning.
  • Deductive reasoning goes from general principles to specific conclusions.
  • Example: Premise 1: All humans are mortal. Premise 2: Socrates is a human. Conclusion: Socrates is mortal.
• Skepticism of Pure Observation: Senses can deceive, but reason provides indubitable truths.

Contrast with Empiricism

• Empiricists (like Locke and Hume) claim knowledge comes from sensory experience.
• Rationalists believe in innate ideas and deductive reasoning.
  • Innate ideas mean that certain knowledge is present at birth.
  • Deductive reasoning means deriving truths from logical principles rather than observation.

Contributions to Psychology

• Rationalism influenced psychological thought by emphasizing the mind's role in structuring knowledge.
• This emphasis is later seen in Kant’s transcendental idealism.
• It inspired cognitive psychology’s focus on mental processes.

Criticisms of Rationalism

• Rationalism has an over-reliance on abstract reasoning without empirical verification.
• It faces difficulty explaining how innate ideas arise.

Key Rationalist Philosophers

• Baruch Spinoza
• Gottfried Wilhelm von Leibniz
• Thomas Reid
• Immanuel Kant
• Georg Wilhelm Friedrich Hegel
• Johann Friedrich Herbert

Baruch Spinoza

Personal Background

• Baruch (Benedictus) Spinoza (1632–1677) was a radical and controversial 17th-century philosopher.
• His life included intellectual brilliance, religious excommunication, and defiance of traditional authority.
• Born on November 24, 1632, in Amsterdam, Netherlands, to a Portuguese-Jewish family.
  • His family were conversos (Jews forcibly converted to Christianity in Portugal).
  • His father, Miguel Spinoza, was a merchant.
  • His mother, Hanna Debora, died when he was 6.
• The family belonged to Amsterdam’s Sephardic Jewish community.
• He attended Jewish Talmud Torah school, studying Hebrew, Torah, Talmud, and medieval Jewish philosophers (Maimonides, Gersonides).
• He was also educated in secular subjects (Latin, science, Descartes’ philosophy) by non-Jewish tutors.

Crisis and Excommunication (1656)

• Spinoza began doubting traditional Jewish doctrines (e.g., miracles, divine authorship of the Bible).
• He was influenced by Descartes’ rationalism and secular thinkers.
• He developed unorthodox views on God, nature, and the soul.
• On July 27, 1656, at age 23, the Amsterdam Jewish community issued a harsh ban (herem) against him.
  • Excommunication is a religious penalty that excludes someone from participation in the sacraments and other privileges of a church.
  • He was accused of