To say that there is a soul in stones simply in order to account for their production is unsatisfactory: for their production is not like the reproduction of living plants, and of animals which have senses. For all these we see reproducing their own species from their own seeds; and a stone does not do this at all. We never see stones reproduced from stones; ... because a stone seems to have no reproductive power at all.
Albertus MagnusEvidence of this [transformation of animals into fossils] is that parts of aquatic animals and perhaps of naval gear are found in rock in hollows on mountains, which water no doubt deposited there enveloped in sticky mud, and which were prevented by coldness and dryness of the stone from petrifying completely. Very striking evidence of this kind is found in the stones of Paris, in which one very often meets round shells the shape of the moon.
Albertus MagnusIn this way, if you continue all the time in the way we have described from the beginning, it will become as easy and clear for you to remain in contemplation in your inward and recollected state, as to live in the natural state.
Albertus Magnus