Natural Sciences: Scope
Unit knowledge question: “Is there solid justification for regarding knowledge in the natural sciences more highly than knowledge in another area of knowledge?”
What Makes a Natural Science?
The defining feature is subject matter: the natural sciences study the natural world as it exists independent of human beings. Their subject matter would exist even if humans did not. Hydrogen is the lightest element; the Sun will shine after we are gone; these are true with or without us. By contrast, economics, history, and the arts study things that depend on human beings being there to create them.
The defining method is the search for — explanations that draw only on matter, energy, and natural forces, excluding supernatural causes.
The four main disciplines — physics, chemistry, biology, and earth sciences — each study a different aspect of the natural world.
Pure and Applied Science
seeks general models and theories — knowledge for its own sake. The direction of fit points toward the world: the scientist revises their theory when reality contradicts it. uses established theory to solve a practical problem. The is reversed: the world must be changed to meet a safe specification.
| Pure science | Applied science | |
|---|---|---|
| Motivation | Curiosity; knowledge for its own sake | Solve a practical problem |
| Product | General models and theories | Working technology |
| Direction of fit | Knowledge fits the world | The world fits the specification |
An important insight: applied science can have a profound effect on human life through risk assessment even without precise predictive power. Probabilistic knowledge — “the risk is high enough to evacuate” — is genuinely useful knowledge.
Science, Non-Science, and Pseudoscience
| Category | What it is |
|---|---|
| Science | Systematic, testable knowledge of the objective world |
| Non-science | Legitimate knowledge of things inherently human |
| Pseudoscience | Claims that look scientific but cannot be properly tested |
is not lesser knowledge — it is different knowledge, about things that require different methods. The dangerous category is , which mimics the appearance of science while being immune to refutation.
The key test is (Karl Popper): a scientific claim must be capable, in principle, of being shown false. A — one that can explain any possible outcome — is not scientific.
A historical caveat: the boundary between science and pseudoscience is not sharp and has changed over time. Isaac Newton was an alchemist; Galileo wrote astrological predictions. In 200 years, which of today’s beliefs might look like alchemy?