Substance

"Substance" carries multiple distinct meanings across philosophy, science, and everyday language, each fundamental in its own way.

Meanings

Substance (philosophy) — that which persists through change; the underlying reality beneath appearances

Substance (chemistry) — matter with a definite composition, whether elemental or compound

Substance (psychology) — psychoactive chemicals affecting consciousness and behavior

Substance (rhetoric) — meaningful content; the weight of an argument versus its form

Related

Identity, Natural Resources, Inertia, The universe's structure, Careful observation