Generation signifies the origin or the procession of some being, called the generated, from another being which is generating.¹⁹ Generation is the opposite of creation. Generation in its special and most proper mode is the production or natural result of a new living organic individual.

Supposit is defined as a complete substance subsisting independently (incommunicabiliter).²⁰

Biogenetic generation is the production of a new living supposit from some other living supposit or supposits, but not from non-living material.²¹

Abiogenetic generation is the production of a new living thing generated by a body or brute material lacking all life. Abiogenetic generation is also called "spontaneous generation" because the new living organic supposit, by its own nature, or without any causal influence of something living, is generated from non living material.²²

Special intervention of God, in this case, signifies that God produced the substantial form, or the soul of the first organic living thing, dependent on some antecedent material, and soul was created by eductive action (man being a case aside) dependent on the merely passive potency of the material, and in no way dependent on some active or exigitive potency of the material.²³ This Divine Intervention does not mean a miracle, nor creation, nor general governance.