I fear, this definition can hardly stand. It contradicts the now established axiom, Omne vivum ex vivo, and we may add, per vivum. If the generative products were themselves dead matter, no life could come out of them. Generation is now recognised as a mode of growth of living things. In baptism indeed the soul comes to be spiritually alive from being spiritually dead: in the order of grace it is brought from not living to living: but that is more like resurrection than generation. Hence in Romans vi, 3-11; Ephesians ii, 5, 6; baptism is compared to resurrection from the dead. But the transition in thought is easy from resurrection to new life, and from new life to new birth, or regeneration. Hence baptism is called the sacrament of regeneration. Cf. John iii, 3-5; Titus iii, 5; 1 Pet. i, 3.

Of God and His Creatures: 4.59