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# Whole-Parts Strategies in Quantum Chemistry: Some Philosophical and Mereological Lessons

## Details

**Authors** Llored, Jean-Pierre

**Year** 2014

**Publisher** HYLE: International Journal for Philosophy of Chemistry

**Kind of work** article

**Discipline** Chemistry

**Secondary disciplines** Philosophy

**Applied** false

[Read it](https://hyle.org/journal/issues/20-1/llored.htm)

## In authors' words

### What they set out to do (purpose)

To show, through the history and laboratory practice of quantum chemistry, how chemists negotiate the relationships between a molecule, its parts, and its environment, and to draw lessons for debates on emergence, reduction, and mereology.

### How they did it (methods)

Historical and philosophical analysis of quantum-chemical approaches (including Mulliken's LCAO-MO method and work associated with Pauling and Bader).

### What they found (results)

The author finds that quantum chemists use whole, parts, and environment simultaneously; that wholes and parts are co-defined (coefficients and atomic charges depend on the whole molecule); that the mereology in use is not classical transitive mereology; and that chemical practice shows co-dependent levels rather than a single fundamental level. Parts and wholes are described as depending on the mode of access, instrumental or cognitive.

## Commentary

### In short

A philosophy-of-chemistry study of how quantum chemists treat molecules and their parts. It finds that wholes, parts, and environment are defined together in practice, and that what counts as a part depends on how it is accessed.

### Response

The finding bears most directly on part-whole structure (S), with the dependence of part identity on mode of access touching perspective (P) and the mutual dependence of whole and part touching relationship (R). Caveats: the paper's non-classical mereology is its own formulation and does not use the four-structure vocabulary; perspective is inferred from the 'mode of access' argument, and the classification rests on a summary of the paper rather than a full reading. No DOI was found.

**Patterns it shows** S, R, P

Shows the structure is there

**Added** 2026-10-16

**How to cite this** Llored, Jean-Pierre (2014). Whole-Parts Strategies in Quantum Chemistry: Some Philosophical and Mereological Lessons. HYLE: International Journal for Philosophy of Chemistry.