*Substance theory, in philosophy, that element of an object without which it wouldn't exist, or what exists only by itself (causa sui)Chemical substance, in chemistry, any material with a definite chemical compositionSubstance (rapper)Substance (Joy Division album)Substance (New Order album)Substance, a song by Haste The Day from the EP That They May Know You and redone for the album Burning Bridges, a tactical espionage video game See also:matter… (More on Substance)