On the Origin of Species Darwin's ideas with those of Lamarck and Goethe while still reflecting the spirit of "Naturphilosophie". Their ambitious programme to reconstruct the evolutionary history of life was joined by Huxley and supported by discoveries in palaeontology. Haeckel used embryology extensively in his recapitulation theory, which embodied a progressive, almost linear model of evolution. Darwin was cautious about such histories, and had already noted that von Baer's laws of embryology supported his idea of complex branching. Asa Gray promoted and defended "Origin" against those American naturalists with an idealist approach, notably Louis Agassiz who viewed every species as a distinct fixed unit
Essay on the Origin of Languages Essay on the Origin of Languages Essay on the Origin of Languages () is an essay by Jean-Jacques Rousseau published posthumously in 1781. Rousseau had meant to publish the essay in a short volume which was also to include essays "On Theatrical Imitation" and "The Levite of Ephraim." In the preface to this would-be volume, Rousseau wrote that the "Essay" was originally meant to be included in the "Discourse on Inequality", but was omitted because it "was too long and out of place". The essay was mentioned in Rousseau's 1762 book, "Emile". In this text, Rousseau lays out a narrative