When Lotze published these works, medical science was still under the influence of Schelling's philosophy of nature. The mechanical laws, to which external things were subject, were conceived as being valid only in the inorganic world. Mechanism was the unalterable connexion of every phenomenon "a" with other phenomena "b", "c", "d", either as following or preceding it; mechanism was the inexorable form into which the events of this world are cast, and by which they are connected. The object of those writings was to establish the all-pervading rule of mechanism. But the mechanical view of nature is not identical with the materialistic. In the last of the above-mentioned works the question is discussed at great length how we have to consider mind, and the relation between mind and body; the answer is we have to consider mind as an immaterial principle, its action, however, on the body and vice versa as purely mechanical, indicated by the fixed laws of a psycho-physical mechanism.