Hylomorphic (from Greek hylē for matter and morphē for form) is an influential philosophical concept, most notably from Aristotle, describing all physical things as a composite of matter (the stuff it's made of) and form (its structure, essence, or organizing principle). This doctrine explains how objects persist through change (a statue remains a statue even if the bronze changes) and how living things are unified wholes, where form gives matter its specific function and identity, like an acorn's form directing it to become an oak tree, not a pine.  

Key Aspects of Hylomorphism:

Matter (Hylē): 
The physical stuff, potential, or substrate of an object (e.g., the bronze of a statue, the flesh of a human). 
Form (Morphē/Eidos): 
The defining structure, essence, or active principle that makes the matter into a specific kind of thing, giving it purpose and function (e.g., the statue's shape, the soul in a living being). 
Composition: 
Objects aren't just matter plus form; they are a unified compound of both, inseparable in reality, though conceptually distinct. 
Explains Change: 
It accounts for how things change yet remain the same entity, as form provides continuity through material alteration (e.g., a growing plant). 
Explains Identity: 
Form explains why a collection of matter is this specific thing and not another, unifying parts into a whole. 

Examples:

A Statue: Bronze (matter) shaped into a particular figure (form). 
A Living Being: Flesh and bone (matter) organized by a soul or life-principle (form), enabling biological functions. 
An Acorn: The acorn's inherent form directs its matter to grow into an oak tree. 

Significance:

Hylomorphism was foundational for medieval Christian philosophy (especially Thomas Aquinas) and remains a key concept in contemporary metaphysics, philosophy of mind, and discussions about personal identity and emergence.