Since the late 19th century, the image of Alexander von Humboldt has been fractured into that of the patient and assiduous fact-gatherer, devoted to measurement and quantification, and that of the sensitive soul, awake to the unity and beauty of the landscape. Concern with emotional and aesthetic responses to the natural world was, however, central to Humboldt's precise and quantitative approach to natural history. The unity of his project may be better understood by exploring his youthful immersion in Enlightenment debates over the nature of the human mind and the possibility of rational knowledge of nature — debates which took on a special urgency during the epoch of the French Revolution. Specifically, the reforms of natural history which Humboldt proposed in the 1790s and practiced during his expedition to the Americas (1799–1804) drew on the concepts and techniques of “analysis” developed by the French Encyclopedists and refracted through German politics and philosophy. Humboldt's approach to natural history thus exemplifies the essential continuity between Enlightenment doctrines of sensation and sensibility and Romantic assertions of the unity of nature and the unique role of the naturalist in revealing that unity.

In 1869, the hundred-year anniversary of Alexander von Humboldt's birth, there were a number of memorial events within German-speaking Europe. In affirming Humboldt's importance, late 19th century liberal natural scientists also promoted their own intellectual pursuits, arguing for the central importance of natural science within both contemporary culture and human history. Humboldt's memorializers used his image to argue for an intimate connection between scientific, moral, and political progress. Within this broad consensus, Humboldt's meaning could be defined in a number of ways, and memorial speakers' own scientific and political commitments shaped their picture of the famous scientist. At the same time that scientists were asserting Humboldt's overwhelming importance for the history of Western culture, however, changes within natural science itself were making it harder to articulate arguments for his universal intellectual significance.

After nearly one hundred years since Humboldt's return to Europe from the Americas, there is little about the famous traveler and naturalist that has not been written on already. A close scrutiny of his scientific legacy, however, reveals important scientific findings of his travels that had not been fully analysed in the past, namely his contributions to the study of palms and his influence on explorers and naturalists who followed his path in the American tropics. In the following essay, I explore in particular Humboldt's contributions to the knowledge of the peach palm (Bactris gasipaes H.B.K.) and his relationship with the French chemist Jean Batiste Boussingault, who visited Venezuela in 1822–1823.

Alexander von Humboldt paid a short visit to the United States at the end of his famous travels in the New World. In Philadelphia, he met the leading scientists of the country. More importantly, President Jefferson invited him to Washington where he supplied the government with the latest statistical and geographical facts about New Spain (Mexico). Jefferson appreciated Humboldt's scientific achievements; Humboldt found Jefferson's Notes on Virginia a model of how to describe a region. Between Humboldt and Albert Gallatin, the Swiss-born Secretary of the Treasury, a lasting friendship developed based on common interests, e.g., in monetary questions.

Humboldt's interests with regard to the U.S. were centered around three topics: the spread of slavery and its consequences in terms of the maintenance of the Union; the mining of gold as compared with Russia; the possibilities of building a canal between the Atlantic and Pacific oceans.

The debate over the slave question caused Humboldt to increase his criticism of American politics. He used his influence in Prussia to have a law passed that prohibited the ownership of slaves, thereby signaling his opposition to slavery to American leaders. In addition, Humboldt envisioned the improvement of international relations through free trade, and therefore favored projects such as an inter-oceanic canal. He never stopped admiring the achievements of the new nation in the sciences. That is why he liked to call himself “half an American.”

The complex subject-matter of the 21^st century world presents an enormous challenge to a discipline-based scientific system. Transdisciplinarity is demanded; it goes beyond interdisciplinarity and focuses both on the relevance of research to the problem at hand and on the feasibility of conducting and implementing it. Problem areas in which different sectors of society and academia may make effective contributions to include new technologies like genetic engineering, biotechnologies, energy, mobility, and nutrition; the creation, organization, and distribution of welfare and resources; human health, age, urban and regional development, and North-South cooperation; new modes of learning, new social systems and decision-making processes; and environmental issues like climate, biodiversity, soil, water, air, recycling, and waste.

Real-world problems determine the kind of action to be taken and not, or at least to a distinctly lesser degree, the competence or the instruments available at any given time. Transdisciplinary research adopts an integrative approach to identifying such problems and working towards solutions. Industry, business, public administration, non-governmental organizations, and consulting firms all possess know-how which may be as important to developing new solutions as the knowledge generated and collected by universities or other scientific institutions. Thus, transdisciplinarity is a vital means of appropriately confronting many of the challenges of the present century. It also promises better and quicker solutions at lower costs, since its value lies not only in its potential for efficiently solving real-world problems but also in its ability to identify such problems at an early stage.

It is the purpose of the present contribution to show, by way of example, how Alexander von Humboldt, who received his education in a time when the modern clear-cut distinction of science and art did not yet exist, aimed at an inter- and transdisciplinary comprehension of his World, and how his ideas became implemented in the second half of the past century in the form of application-oriented long-term ecosystem research.

Humboldt and the Ocean. A Synopsis of his Contributions to Marine Sciences. During his “Journey to the Equinoctial Regions of the New Continent” about 200 years ago, Alexander von Humboldt (1769–1859) made many oceanographic observations in the North Atlantic and Eastern Pacific Ocean. His main interest was the interrelation between climate and global ocean circulation, which is still one of the major topics in current marine research. Ever since, in 1790, he first saw the open ocean at the North Sea coast, when he, in the company of Georg Forster embarked on his trip to England, Humboldt had a longing for the ocean, especially the Pacific, and a strong interest in matters relating to oceanography. Unfortunately his marine texts are scattered over his major publications, many notes have never been published. Humboldt did not finish his decade-long work on “Oceanica,” a synopsis of his marine natural history ideas. Meanwhile it is generally accepted that Humboldt, although not an oceanographer in the modern meaning of the word, certainly belongs to the list of pioneers of marine sciences. Geographers and oceanographers of Kiel University, have especially covered Humboldts lasting marine legacy in the last century. His innovative and classical concepts of climate-driven thermohaline ocean circulation are background for some current international marine research projects.

In the spirit of the second volume of Cosmos, we consider two worldviews that arose in the ancient Near East and are with us yet. For one, the heart of the world is wilderness. For the other, the word revolves around the city, the work of human hands. These two worldviews belonged to two kinds of civilization (each with its characteristic kind of farming): those of the hilly uplands and those of the great river valleys. The first kind is typified by the Canaanites and Israelites, the second by the Mesopotamians. The myth of the World Mountain is shown to have a basis in ecological fact: wilderness as the source of life. Eden is here identified with the wild World Mountain or Mountain of God, from which humans are necessarily exiled. As soon as we become fully human, we begin to destroy Eden and so expel ourselves. With the above dichotomy in mind, we ask: Was Humboldt a man of the Mountain or of the Tower?

Alexander von Humboldt has been a neglected figure in American intellectual and cultural history. His visit to the United States in 1804, his many connections with American scientists, explorers, politicians, writers, and artists, and the wide popularity of his books, all show Humboldt to be of great significance to nineteenth-century America. This essay traces the course of Humboldt's fame in Victorian America, the reasons for his special connection with the United States and for the precipitous decline in his reputation, and closes with a consideration of Humboldt's legacy in American art and literature.

Many changes have taken place in Amazonas Province of Venezuela, since Alexander von Humboldt's trip to the region. The most important changes today are in the way that land, which is inhabited by indigenous peoples, is being developed. There is an emphasis on small-scale, non-exploitative, sustainable agriculture, and on forest industries that are locally owned and operated. Cooperation with and protection of indigenous peoples and their environment, as opposed to the devastation caused by large-scale corporate industry, is of the utmost importance. This is very much in keeping with the legacy of Alexander von Humboldt.

Starting from Alexander von Humboldt's always ambivalent attitude towards Potsdam, the city which made him an honorary citizen and where he conceived large parts of his Cosmos, this contribution tries to show, through a broad analysis of Humboldt's early letters and later writings, the complex relation between world image and world travel, between science and cosmopolitanism. Humboldt's innovative concept of science, at the same time transdisciplinary and intercultural, connects in its ethical dimension with ideas of Immanuel Kant, as Kant had presented them in his “Idee zu einer allgemeinen Geschichte in weltbürgerlicher Absicht.” In this respect it becomes evident that the evolution of Humboldtian science is not possible without considering his understanding of cosmopolitanism, just as it is not possible to understand the specific kind of cosmopolitics which makes the Prussian scientist, author and intellectual an important connecting link for the actual definition of cosmopolitanism and cosmopolitics. The realization of world-wide communication networks between the most different sciences and scientists should, as the material infrastructure, be the presupposition of a global thinking which can be seen as part of a project of the (European) modernity. The biographical as well as the historical background of Alexander von Humboldt's deliberations should, however, not be forgotten.