This attempt at a system of rational geology was a great advance in the right direction, though many gaps still remained to be filled up and some errors to be corrected; such for instance as the idea adopted by Generelli from Moro, and maintained in other parts of his work, that all the stratified rocks are derived from volcanic ejections. Nevertheless, geology, by the middle of the eighteenth century, had evidently begun to pass gradually, though very slowly, from the stage of crude and fanciful hypotheses to that of an inductive science. But even then the observers had only succeeded in setting foot on the lower slopes of a peak, the summit of which will not be reached, if indeed it ever be, for many a long year to come. During the next half of the century progress was made, now in this direction, now in that; slowly truths were established, slowly errors dispelled; and as the close of that century approached, the foundations of modern geology began to be securely laid. A great impulse was given to the work, though to some extent the apparent help proved to be a real hindrance, by that famous teacher, Werner of Freiberg, in Saxony. His influence was highly beneficial, because he insisted not only on a careful study of the mineral character of rocks, but also on attending to their grouping, geographical distribution, and general relations. It was hurtful almost to as great a degree, because he maintained, and succeeded by his enthusiasm and eloquence in impressing on his disciples, most erroneous notions as to the origin of basalts and those other igneous rocks which were formerly comprehended under the name "trap." Such rocks he stoutly asserted to be chemical precipitates from water, and, besides this, he held views in general strongly opposed to anything like the action of uniform causes in the earth's history. In short, the Saxon Professor was in many respects the exact antithesis of Lyell, and the points of essential contrast cannot be better indicated than in the words of the latter.[59]