Thomas Aquinas

“ But at the first beginning of the world the active principle was the Word of God, which produced animals from material elements, either in act, as some holy writers say, or virtually, as Augustine teaches. Not as though the power possessed by water or earth of producing all animals resides in the earth and the water themselves, as Avicenna held, but in the power originally given to the elements of producing them from elemental matter by the power of seed or the influence of the stars. ”

“ The bodies of birds and fishes may be considered from two points of view. If considered in themselves, it will be evident that the earthly element must predominate, since the element that is least active, namely, the earth, must be the most abundant in quantity in order that the mingling may be duly tempered in the body of the animal. ”

“ Further, fishes and birds are not produced from water only, but earth seems to predominate over water in their composition, as is shown by the fact that their bodies tend naturally to the earth and rest upon it. It is not, then, fittingly that fishes and birds are produced from water. ”