Dialectics of Nature

Engels wrote most of the manuscript between 1872 and 1882, which was a melange of German, French and English notations on the contemporary development of science and technology; however, it was not published within his lifetime.

In later times, Eduard Bernstein passed the manuscripts to Albert Einstein, who thought the science confused (particularly the mathematics and physics) but the overall work worthy of a broader readership.

It includes the famous "The Part Played by Labour in the Transition from Ape to Man", which has also been published separately as a pamphlet.

Engels argues that the hand and brain grew together, an idea supported by later fossil discoveries (see Australopithecus afarensis).

Most of the work is fragmentary and in the form of rough notes, as shown in this quotation from the section entitled "Biology": Vertebrates.