Abstract

Steno described in 1669 geological sections which were interpreted as the result of a series of earlier events. Steno used actuogeological methods. This was the first step towards temporalizing nature. Steno was succeeded by a lot of other researchers from different European countries. It is amazing to see, that “actualism” was widespread during the 18th century. The next step was the discovery that fossils are extinct beings (Ray, Hooke and others). Using methods of comparing anatomy W. Hunter (forerunner of Cuvier) could prove in 1769 that the Mastodon is an extinct vertebrate. The work of Soulavie in France (1780) is stressed. He held in his hand the key for solving the problem of index‐fossils. About 1800 the importance of fossils for stratigraphy and describing a history of the earth was recognized. Theories and hypotheses were needed to explain the fossil documents (strange shells in older strata and higher developed mammals in younger strata). All these theories couldn't propose a feasible mechanism for the change of beings during the history of the earth. But it could be said, that all fossils proove a history of life and the earth i. e. a progressive development in one sense, a development which is not reversible.