Contemporary history and philosophy of science shows renewed interest in traditional questions about the origin and distribution of life on Earth. One contributor to this trend is the development of astrobiology, an interdisciplinary field that combines biological, chemical, geological and astronomical research. Two currents of research can be observed in the literature. One stream follows astrobiological research and focuses on the question of the existence of life in the universe; the other focuses on the past – it strives to re-evaluate various nineteenth- and twentieth-century theories and essential ideas about the origin and development of life that have been renewed in modern natural sciences. Although one might dismissively claim that there is no real value in studying the viewpoints found in the ‘graveyard of theories’, historians and philosophers of science, as well as scientists themselves, might reply that those half-forgotten theories can represent the key to the development and better understanding of modern science. Andreas W. Daum’s concise biography of Alexander von Humboldt enables us to do exactly that.

My admiration for the book begins with its cover. One encounters a prominent image of the young Alexander von Humboldt. And although that image alone can say much about the famous explorer, the background reveals much more about his personality and life. The lower half is covered with a picture of mountains, associating those already familiar with the subject (but also the first-time reader) with the common knowledge that Humboldt reached the peaks of several mountains on his many travels, the most famous being Chimborazo. The upper half of the cover features a discrete geographical pattern of the map. This pattern represents an adequate design considering the fact that Humboldt was a naturalist and an international, cross-continental explorer. His home was divided between Prussia and France, Europe and South America; on his many travels, he even took an opportunity to visit Russia. Beyond the cover design, one cannot but admire the exceptional quality of the paper, which will be especially suitable for those who like to mark or underline the text. Daum writes clearly, and at some moments his descriptions seem to reflect the poetic style of Humboldt himself as he paints the picture of the Prussian’s life and troubled, yet inspired and ever-active, mind. The pages are filled with various pictures, the most famous representing the Naturgemälde that inspired Humboldt’s theory in Cosmos. Specialist scholars, as well as the general public, will enjoy this read.

Alexander von Humboldt was a Prussian naturalist and explorer. Some remember him for the discovery of isothermal lines and the so-called Humboldt current in the Pacific Ocean. Others remember him as one of the founders of Humboldt University in Berlin (the other being his brother, Wilhelm von Humboldt). Some, on the other hand, remember him by names of various overseas species: Lillium humboldtii, Hylocharis humboldtii, Spheniscus humboldtii and so on. Humboldt’s name is also borne by many geographical phenomena, such as the Humboldt river and Lake Humboldt in Nevada, Humboldt Peak in Colorado, and the Humboldt mountains in New Zealand. Finally, Humboldt’s observations about humanity’s harmful impact on ecosystems and nature have made him an inspirational figure in contemporary ecology. Humboldt was and remains a popular figure in science. Yet this popularity came at the cost of a certain degree of idolization and mystification of his personality and achievements. Daum attempts to demystify Humboldt and reveal him as the nineteenth-century figure he was: a brilliant but emotional friend of Goethe; focused but very often distracted and divided between distinct, even opposing, ideas; a connoisseur and follower of Immanuel Kant, Friedrich Schiller and Friedrich Schelling; a Romantic scholar who wanted to unite science and natural phenomena.

Although the title suggests that it is a short biography of one of the greatest minds of the nineteenth century, Daum’s descriptions of Humboldt’s life are skilfully interwoven with his scientific and philosophical insights about nature. The descriptions of Humboldt’s childhood foreshadow the explorer who would set off on a transoceanic journey to South America. The depiction of the relationship with his brother highlights their differences, which would manifest in their diverging career paths: Wilhelm focused on linguistic and legal studies, while Alexander followed his passion for natural studies. Daum masterfully describes how Humboldt’s focus on precise scientific measurements and observations, grounded in his pursuit of objectivity in science, often intertwined with his emotional, even distracted – subjective – moments, which inevitably shaped his scientific methodology. Humboldt did not ‘invent nature’ any more than Charles Darwin ‘discovered evolution’. But Humboldt was one of the first scholars to attempt to represent nature as a Whole of interconnected natural phenomena. For Humboldt, the goal of scientific research was to discover the causes of these phenomena and explain their action within the Whole.

Daum correctly observes that Humboldt’s most famous work – Cosmos – reflects different aspects of Humboldt’s personality. I might add that such a characteristic only increases the beauty and value of this work. Through numerous aesthetic descriptions, disjointed arguments and observations, Cosmos offers us a glance into the extraordinary, somewhat chaotic, but no less brilliant mind of Alexander von Humboldt. And this is precisely what Daum’s book enables us to do. Just as Humboldt became ‘a mediator between science and the humanities’ (p. 152), so is Daum a mediator between nineteenth-century Humboldt and the idolized Humboldt we often encounter in the literature today. Daum’s book allows us to see how Humboldt’s naturalistic ideas have been renewed in the science of the twentieth and twenty-first centuries.