Locke vs. Hume: Innate Ideas, Causality, and Knowledge

Posted on Dec 2, 2024 in Philosophy and ethics

1) Locke and Hume: Innate Ideas

Hume agrees with Locke that there are no innate ideas, a core tenet of empiricism: all knowledge comes from experience. Our ideas derive from impressions; we cannot conceive of anything without prior sensory input.

Locke, however, argues that while all mental content are ideas, some, like passions and natural instincts, are innate, stemming from our inherent mindset, not external sensations.

2) Impressions and Ideas

Are there impressions derived from ideas? No. Impressions of reflection may precede their corresponding ideas, but all ideas ultimately stem from sensory experience. Ideas of sensation derive from impressions of sense (Treatise, Part One, Section Two).

3) Simple Impressions and Ideas

Hume argues that simple ideas derive from simple impressions. If one lacks the capacity for a certain impression, the corresponding idea cannot exist. An exception might be conceiving a color hue on a sliding scale without direct experience, but this is irrelevant to the principle (as Hume states in his Enquiry).

4) Hume’s Apparent Contradiction

Hume asserts that all ideas originate from corresponding impressions, yet also acknowledges ideas not directly derived from impressions. This is resolved by the imagination’s ability to decompose complex ideas into simple ones (not necessarily copies of impressions) and recombine them into novel complex ideas unrelated to prior experience.

5) Berkeley’s Contribution

Hume credits Berkeley with the crucial discovery that general ideas are merely particular ideas associated with a term, giving them broader significance.

6) Types of Knowledge

Hume distinguishes two types of knowledge:

  • Relations of Ideas: Includes geometry, algebra, and arithmetic. These propositions concern relationships between ideas (e.g., whole and part) and are reached through reason alone, independent of experience. They are:
    • Necessary truths: Their opposite is impossible, a contradiction.
    • Analytic truths: The predicate is contained within the subject.
    • Explanatory truths: They clarify existing knowledge.
    • A priori truths: Independent of experience.
    In logic and mathematics, we achieve absolute certainty.
  • Matters of Fact: Depend entirely on experience. Propositions like “gold is yellow” require observation. They are:
    • Synthetic truths: The predicate is not contained within the subject.
    • Contingent truths: Their opposite is possible without contradiction.
    • Ampliative truths: They expand our knowledge.
    • A posteriori truths: Dependent on experience.
    Only experience guarantees the truth of factual propositions. We can be sure of what is present to the senses or memory, but not what transcends these limits, as any event’s opposite is always possible.

7) Critique of Causality Proofs

Hume critiques arguments for the principle of causality:

First Argument: Everything must have a cause; otherwise, it would create itself, implying prior existence, which is impossible.

Critique: To say something arises without cause is not to say it causes itself, but that it lacks a cause. The argument assumes what it denies: a prior cause.

Second Argument: What is uncaused is caused by nothing, but nothing cannot cause anything.

Critique: The question is whether everything needs a cause, not whether something or nothing can be a cause.

Third Argument: Every effect must have a cause, as it is inherent in the idea of an effect.

Critique: This doesn’t mean every being must have a prior cause. From “every woman has a husband,” we cannot infer “every man must be married.”

8) Causal Relationships and Probability

Causal relationships are not known through relations of ideas but through experience. We cannot claim they are probably true because:

  • This would be either necessary knowledge (which experience cannot provide) or probable knowledge based on prior experiences, leading to an infinite regress.

9) Causality Not a Relation of Ideas

Causality is not intuitively or demonstratively certain. Cause and effect are distinct, separable ideas, and their connection involves no logical contradiction. The absence of causal relationships is as conceivable as their existence.

10) Criticisms of Hume on Probable Causality

Critics argue against Hume’s view of probable causal relationships between perceptions:

  1. Skepticism precludes establishing probable truths; if truth is unknown, we cannot assess proximity to it.
  2. Experience cannot yield probability; observed cases divided by infinite possible cases approach zero.
  3. Assuming the future will resemble the past is either a priori certainty (apriorism) or based on past experience, leading to infinite regress.