Hume’s Empiricism: Perceptions, Ideas, and Critique of Metaphysics

Perception: Hume’s Empiricism

Hume believed that all knowledge originates from sensory experience. He argued that the human mind consists of perceptions, categorized as impressions and ideas, differentiated by their intensity. Vivid impressions are what we feel, hear, see, love, and hate. Ideas are fainter copies of these impressions, employed during reasoning. Hume rejected rationalist theories of innate ideas, asserting that all ideas stem from prior sensory impressions.

He further divided perceptions into simple and complex. Simple perceptions (both impressions and ideas) are indivisible, while complex perceptions can be broken down into parts.

Laws of Association of Ideas

  1. Similarity
  2. Contiguity (Space-Time): The mind tends to connect ideas of objects close in space and time.
  3. Cause and Effect: We instinctively link observed events (effects) to their causes. This connection, stronger than mere imagination, forms the basis of Hume’s critique of metaphysics.

Objects of Reason

Hume distinguished between:

  • Relations of Ideas: Certain, intuitive, or demonstrative statements expressing relationships between ideas (e.g., 3 + 2 = 5). Their denial leads to a contradiction.
  • Matters of Fact: Statements based on experience and reasoning, whose denial is not contradictory but merely false (e.g., “I saw a red car”).

Critique of Metaphysics

Hume challenged the rationalist notion of causality as an a priori, necessary connection between cause and effect. He argued that we have no impression of this necessary connection, nor of a constant, unchanging substance.

Causality and its Consequences

Hume argued that the causal connection is a product of habit, leading to skepticism and relativism. Science, based on inductive inferences, can establish probable laws but not necessary connections. Scientific knowledge is constantly subject to revision.

Critique of the Idea of Substance

  • The External World: While we have impressions of external objects, we cannot deductively conclude their continuous existence independent of our perceptions.
  • The Self: We lack a consistent impression of a unified self throughout our lives. The “self” is a bundle of impressions we habitually associate.
  • God: We have no impression of an absolute power or prime mover, making the idea of God invalid according to Hume’s empirical criteria.

Ethical Considerations

Hume viewed ethics as grounded in sentiment rather than reason. Sympathy, the capacity to share others’ feelings, forms the basis of moral judgment. Virtue evokes approval, while vice evokes disapproval, in the observer. Reason plays a secondary role, serving our passions.