Overview

Causality is the agency or efficacy that connects one process (the cause) with another process or state (the effect), where the first is partly responsible for the second, and the second is partly dependent on the first.

Core Idea

The core idea is connection. We assume the world isn’t just a random sequence of events; things happen because of other things. The past determines (or influences) the future.

Formal Definition

The relation between two events, $A$ (cause) and $B$ (effect), such that $B$ happens as a result of $A$.

Intuition

  • Billiard Balls: Ball A hits Ball B, and Ball B moves. We say A caused B to move.
  • Counterfactuals: “If A hadn’t happened, B wouldn’t have happened.”

Examples

  • Domino Effect: A chain reaction of causality.
  • Butterfly Effect: Small causes having large effects in complex systems.
  • Correlation vs. Causation: Just because rooster crows when the sun rises doesn’t mean the rooster caused the sun to rise.

Common Misconceptions

  • Misconception: We can see causality.
    • Correction: David Hume argued we only see “Constant Conjunction” (A always follows B), not the causal power itself. Causality is an inference, not an observation.
  • Misconception: Causes always come before effects.
    • Correction: While true in classical physics, some theories in quantum mechanics and relativity play with retrocausality.
  • Determinism: The doctrine that all events are determined by causes external to the will.
  • Free Will: The ability to choose between different possible courses of action unimpeded.
  • Teleology: Explanation by purpose rather than cause.

Applications

  • Science: The goal of science is often to find causal mechanisms.
  • Law: Determining liability (Did the defendant’s action cause the harm?).
  • Medicine: Finding the etiology (cause) of a disease.

Criticism and Limitations

  • Russell’s Critique: Bertrand Russell argued that “cause” is a relic of a bygone age, and advanced physics deals with functional relationships (equations), not causes.

Further Reading

  • Causality by Judea Pearl
  • A Treatise of Human Nature by David Hume