British Empiricism: David Hume and the Foundations of Knowledge
Empiricism and David Hume (1711-1776)
Philosophical empiricism is fundamentally a British development, flourishing in the 17th and 18th centuries across the British Isles. Its roots can be traced back to the nominalism of William of Ockham and include aspects of Bacon’s scientific theory and Hobbes’ political theory.
Empiricism is characterized by two fundamental aspects:
- Rejection of Absolutes: Denying absolute truth, or at least denying that absolute truth is accessible to humans.
- Primacy of Experience: Recognizing that every truth must be tested through experiment, and that experience can lead to alteration, amendment, or abandonment of ideas.
Empiricism does not oppose reason but denies the possibility of establishing necessary truths—truths so absolute that verification or control becomes absurd or contradictory. Empiricists agree with the Cartesian notion that ideas are the contents of the mind. However, empiricists, more aligned with natural sciences than mathematics, diverge from Descartes regarding the origin and reliability of ideas. Rationalists believe that certain knowledge comes from pure reason, while empiricists argue that all knowledge originates from experience.
Four major ideas characterize empiricism:
1. Denial of Innate Ideas
- No knowledge is independent of experience or sensory data.
- Every abstract idea is ultimately derived from the senses.
- Empiricists advocate the Tabula Rasa (blank slate) theory: we are born with blank minds, and experience fills them with ideas. Knowledge is constructed from impressions. Without sensory data, there is no understanding.
2. Sensory Evidence as the Criterion of Truth
While Cartesians (rationalists) consider an idea true if it is clear and distinct to the mind, empiricists assert that the only criterion for truth is sensory evidence. An idea is true if it corresponds to a sensory impression.
3. Rejection of Ideas Without Experiential Counterparts
Metaphysics is considered illegitimate because concepts like “substance” or “self” lack sensory foundations, as Hume argued.
4. Denial of Universal and Necessary Knowledge
Since sensory experience is mutable and changing, knowledge derived from it is also mutable. For example, one cannot definitively say, “John is my friend,” because future experiences might alter that perception. One can only say, “For now, John is my friend.”
Descartes and Empiricism
Descartes is often presented as the antithesis of empiricism, but the relationship is more complex. Empiricists often define themselves in opposition to Descartes, yet Cartesian thought significantly influenced empiricism, albeit in nuanced ways.
Post-Cartesian philosophy, including empiricism, focuses on the subject and asks, “How do I know?” rather than “What do I know?” This question is central to all philosophy after Kant.
Empiricists reject innate ideas but shift the focus from Plato’s question of Being to the question of knowledge.
Cartesian influence on empiricism manifests in two key areas:
- The Rule of Evidence: The most important rule of Descartes’ method is that we should only accept what is evident. If something is questionable, it should be considered false. Empiricists agree, asserting that knowledge comes from factual experience, what Locke calls “a certain trade matters.”
- The Cartesian Subject: Empiricists adopt the Cartesian notion that real knowledge comes from the subject. Individual experiences are the only source of valid knowledge. The world exists insofar as it is known by someone.
Hume criticized the Cartesian idea of an innate self, arguing that the “I” is merely a bundle of impressions and sensations. While this bundle is constantly changing, it is the provisional source of knowledge.
Empiricists never accept Descartes’ innate ideas or the identification of the “Cogito” with reason. Descartes equated thought and reason, but empiricists believe reason is not self-sufficient; it requires experience. Experience is the source of reason. Consequently, empiricists are both antimentalists and anti-innatists:
- Antimentalists: They consider thought (reason) to be derived from experience, and mental contents to be dependent on sensory content.
- Anti-innatists: They deny innate ideas. Unlike Descartes, who believed innate ideas were spontaneous productions of the mind, empiricists view the mind as a Tabula Rasa.