Protogaea

Unpublished in his lifetime, but made known by Johann Georg von Eckhart in 1719,[2] it was conceived as a preface to his incomplete history of the House of Brunswick.

[3] Protogaea is a history of the Earth written in conjectural terms; it was composed by Leibniz in the period from 1691 to 1693.

[5] The text was first published in full in 1749, shortly after Benoît de Maillet's more far-reaching ideas on the origin of the Earth, circulated in manuscript, had been printed.

[6] Protogaea built on, and criticized, the natural philosophy of René Descartes, as expressed in his Principia Philosophiae.

[9] He took up suggestions of Nicolaus Steno that argued for the forms of fossils being prior to their inclusion in rocks, for stratification, and for the gradual solidification of the Earth.