---
title: "PHI403 Lecture 10 — Is it the Business of Science to Construct Theories?"
type: source
tags: [philosophy-of-science, theory, data, naturalism, hanson, leonelli]
authors: [Anjum, Rani Lill; Rocca, Elena]
year: 2023
venue: "PHI403 Causation in Science, NMBU"
kind: handout
raw_path: "raw/Philosophy of Science/PHI302 10 Is the Business of Science to Construct Theories.pdf"
created: 2026-04-20
updated: 2026-04-20
key_claims:
  - Radical naturalism/empiricism (Bacon) holds science should stick to observation; theory is metaphysical speculation.
  - The problem of underdetermination: any set of data can be explained by multiple theories equally well.
  - Raw theory-independent data is an illusion (N.R. Hanson, Patterns of Discovery) — observation is theory-laden; seeing is an activity.
  - Sabina Leonelli (Data-Centric Biology): data are made, not given; evidential value depends on the inquiry context.
---

# PHI403 Lecture 10 — Is it the Business of Science to Construct Theories?

Addresses the relationship between data and theory. **Radical naturalism** (Hume, Bacon's *Novum Organum*) holds that science should stay within empirical observation; theory construction is metaphysical overreach.

The lecture argues this position is untenable:

- **Underdetermination of theory by data** — any data set admits of multiple theories that fit and explain it equally well.
- **Theory-ladenness of observation** (Norwood Russell Hanson, *Patterns of Discovery*) — "there is more to seeing than meets the eyeball"; an expert and a layperson looking into a microscope do not see the same thing. Seeing is an activity.
- **Data are made, not given** (Sabina Leonelli, *Data-Centric Biology*) — data are products of complex interactions between researchers and the world; their evidential value depends on context.

Data alone cannot supply explanation, prediction, or policy recommendation. We need a **causal theory** to move from observed correlation to actionable claim. Without a theory, data are inert — applicable only to the particular recorded cases.

## Connections
Back-link: [[sources/2023-anjum-rocca-phi403-causation-in-science]]. Concepts: [[concepts/philosophical-bias]] · [[concepts/causation]] · [[concepts/mechanisms-in-science]].