> [!definition]
> **Medium** · *Definition*
>
> What carries or sustains something across: a beam *bears* a load, a wire *carries* a current. A medium can bear without producing.

*Bears*, *carries*, *transmits*, *supports*, *sustains*: verbs of medium, common in philosophy of physics (the field carries the force) and in ordinary metaphysical prose (the relation bears its term). A medium can bear without producing. On productive accounts of causation, production also requires something to bear or transmit what is produced; regularity accounts deny that any further productive relation is needed. Here *medium* names this general transmission operator, not a role-term for Nature or a synonym for the bearer of Physicality, which is Substance ([§1.4.3](<1.4.3 Substance.md>)).


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← [1.5.6 Causation](<1.5.6 Causation.md>) | [1.5.8 Persistence](<1.5.8 Persistence.md>) →
