Carl Friedrich Kielmeyer (1765-1844) was the 'father of philosophy of nature' owing to his profound influence on German Idealist and Romantic Naturphilosophie. With the recent growth of interest in Idealist and Romantic philosophy of nature in the UK and abroad, the importance of Kielmeyer's work is being increasingly recognised and special attention is being paid to his influence on biology's development as a distinct discipline at the end of the eighteenth century. In this exciting new book, Lydia Azadpour and Daniel Whistler present the first ever English translations of key texts by Kielmeyer, along with contextual and interpretative essays by leading international scholars, who are experts on the philosophy of nature and the formation of the life sciences in the late eighteenth century. The topics they cover include: the laws of nature, the concept of force, the meaning of 'organism', the logic of recapitulation, Kielmeyer and ecology, sexual differentiation in animal life and Kielmeyer's relationship to Kant, Schelling and Hegel. In doing so, they provide a comprehensive English reference to Kielmeyer's historical and contemporary significance.