These general lines of thought upon geology and its kindred science of zoology were followed by St. Thomas Aquinas and by the whole body of medieval theologians, so far as they gave any attention to such subjects. The next development of geology, mainly under Church guidance, was by means of the scholastic theology. Phrase-making was substituted for investigation. Without the Church and within it wonderful contributions were thus made. In the eleventh century Avicenna accounted for the fossils by suggesting a "stone-making force";(129) in the thirteenth, Albert the Great attributed them to a "formative quality;"(130) in the following centuries some philosophers ventured the idea that they grew from seed; and the Aristotelian doctrine of spontaneous generation was constantly used to prove that these stony fossils possessed powers of reproduction like plants and animals.(131) (129) Vis lapidifica. (130) Virtus formativa. (131) See authorities given in Mr. Ward's assay, as above. Still, at various times and places, germs implanted by Greek and Roman thought were warmed into life. The Arabian schools seem to have been less fettered by the letter of the Koran than the contemporary Christian scholars by the letter of the Bible; and to Avicenna belongs the credit of first announcing substantially the modern geological theory of changes in the earth's surface.(132) (132) For Avicenna, see Lyell and D'Archiac. The direct influence of the Reformation was at first unfavourable to scientific progress, for nothing could be more at variance with any scientific theory of the development of the universe than the ideas of the Protestant leaders. That strict adherence to the text of Scripture which made Luther and Melanchthon denounce the idea that the planets revolve about the sun, was naturally extended to every other scientific statement at variance with the sacred text. There is much reason to believe that the fetters upon scientific thought were closer under the strict interpretation of Scripture by the early Protestants than they had been under the older Church. The dominant spirit among the Reformers is shown by the declaration of Peter Martyr to the effect that, if a wrong opinion should obtain regarding the creation as described in Genesis, "all the promises of Christ fall into nothing, and all the life of our religion would be lost."(133) (133) See his Commentary on Genesis, cited by Zoeckler, Geschichte der Beziehungen zwischen Theologie und Naturwissenschaft, vol. i, p. 690.