 Of the various kinds of being, substances are what exist in the most proper sense (EpiMeta 4.138 {125}). Among substances, the most familiar are concrete individuals like dogs and stones (EpiMeta 2.58 {43}). But these are composite entities, and since the principles of a substance are themselves even more properly considered to be substances (EpiMeta 1.31 {15–16}; LongAnima II.8), the most fundamental substances in the sensible realm are the metaphysical ingredients of composite substances, matter and form (LongMeta VII.44 {960}).