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
Reactions to On the Origin of Species of Selection". Darwin now worked on an "abstract" trimmed from his "Natural Selection" manuscript. The publisher John Murray agreed the title as "On the Origin of Species through Natural Selection" and the book went on sale to the trade on 22 November 1859. The stock of 1,250 copies was oversubscribed, and Darwin, still at Ilkley spa town, began corrections for a second edition. The novelist Charles Kingsley, a Christian socialist country rector, sent him a letter of praise: "It awes me...if you be right I must give up much that I have believed", it was "just as noble a conception