---
title: "Computer Science as Empirical Inquiry: Symbols and Search"
authors:
  - "Allen Newell"
  - "Herbert A. Simon"
year: 1976
venue: "Communications of the ACM (Turing Award lecture)"
arxiv: null
doi: "10.1145/360303.360308"
source: "https://doi.org/10.1145/360303.360308"
topics:
  - physical-symbol-system
  - search
  - newell-simon
  - ai
seed_rank: 584
seed_batch: "foundations-greats-2026-08-13"
reviewed: "2026-08-13"
pool: "agents"
relevance_score: 9
lineage: foundations-of-computing
cites:
  - title: "The Logic Theory Machine: A Complex Information Processing System"
    url: "https://doi.org/10.1109/TIT.1956.1056797"
    year: 1956
    arxiv: null
    doi: "10.1109/TIT.1956.1056797"
  - title: "Report on a General Problem-Solving Program"
    url: "https://iiif.library.cmu.edu/file/Simon_box00008_fld00538_bdl0001_doc0001/Simon_box00008_fld00538_bdl0001_doc0001.pdf"
    year: 1959
    arxiv: null
    doi: null
see:
  - "580-the-logic-theory-machine-a-complex-information-processing-sy"
  - "582-report-on-a-general-problem-solving-program"
---

# Computer Science as Empirical Inquiry: Symbols and Search

## One-sentence takeaway

Newell and Simon state two empirical laws: a physical symbol system has the necessary and sufficient means for general intelligence, and intelligence is heuristic search.

## Why it matters here

This 1976 Turing Award lecture is still the creed — or the foil — for every Broadside agent that is either a symbol manipulator or a learned approximator of one.

## Key ideas

- A physical symbol system is a machine that manipulates token structures according to processes that themselves are token structures.
- The Physical Symbol System Hypothesis: such systems are necessary and sufficient for general intelligent action.
- The heuristic search hypothesis: problems are solved by generating and testing in a large space, guided by rules of thumb.
- Computer science is an empirical natural science of these systems, not only a branch of mathematics.
- The lecture looks back over LT and GPS as the experimental base.

## Caveats

## Links

- DOI: [10.1145/360303.360308](https://doi.org/10.1145/360303.360308)
- URL: https://doi.org/10.1145/360303.360308