A native of Oldenburg in northern Germany, Jaspers testified in his philosophical autobiography3 to the spirit of critical and independent thinking that his father cultivated in him from the start. His grandfather had been a Lutheran pastor, while his immediate family seems to have been theistic but anti-ecclesial. After some initial studies in law, he changed to medicine and trained under well-known pathologists and psychiatrists in the clinic at the University of Heidelberg before the First World War. His first large-scale work, General Psychopathology (1913), a ground-breaking text in that field, is the result of his reflections on that experience. His second major scientific work, Psychology of Worldviews (1919), shows his developing interest in philosophical problems and methods.
Jaspers’s formal transfer from teaching psychiatry to philosophy at Heidelberg permitted him to begin issuing a long stream of philosophical books and articles, most notably the three-volume general exposition of his viewpoint tided simply Philosophy (1932). The philosophy faculty proved to be a post that better suited his mind and his delicate health. From childhood he had suffered from bronchial and cardiac problems, but a stern discipline in matters of work and rest, and the constant support of his wife, Gertrude (whom his autobiography describes as his intellectual soulmate), made possible a career of teaching and writing until the Nazis severed his academic connections in 1937 because of displeasure with his acute criticism of racism and rabid nationalism. Gertrude’s Jewish heritage was also held against him, but they were spared the fate of deportation or worse, and in private retirement during the war Jaspers was able to continue to write.
Although much material remains in unpublished manuscripts to this day, he did publish a score of books, including several volumes of historical commentary called The Great Philosophers and a thoroughgoing restatement of his own system in his treatise On Truth. Two of his lecture series gave a more succinct expression to his ideas: Reason and Existence and Philosophy of Existence. In these studies one sees a trait that sets him apart from many of his fellow existentialists, whose suspicions about science and technology he critiques in the course of his own on-going appreciative engagement with both the fruits of modern science and the habits of thinking typical of a scientific mind. His post-Second World War books also enter the dialogue of existentialism with religion. They include a debate on the demythologizing of the Scriptures, which he conducted with Rudolph Bultmann (Myth and Christianity), as well as several volumes of discussions with Protestant theologians (Philosophical Faith and the subsequent Philosophical Faith and Revelation).
In 1948 Jaspers left Heidelberg for a post at the University of Basel in Switzerland. Before his death in 1969, he also published a popular introduction to his philosophy (Way to Wisdom), a sophisticated reflection on the atomic age (The Atomic Bomb and the Future of Mankind), and his long-nurtured views on the philosophy of history (The Origin and Goal of History). It is this book that contains his famous theory of the Axial Age of history, the period from about 600 B.C. to 400 B.C. in which Chinese, Indian, Persian, Hebrew, and Greek thinkers all independently generated many of the political and metaphysical ideas that have been most decisive in shaping the rest of human history.
In Jaspers’s own judgment, the figure that was most important for the shaping of his own thinking was Immanual Kant, but he also credits Søren Kierkegaard, Friedrich Nietzsche, and Max Weber with inspiring his work.4 His readers, however, cannot help noticing the strongly Neoplatonist cast to much of his thought, and the four figures whom he quotes again and again are Plotinus, Bruno, Spinoza, and Schelling. The metaphysical matrix that in some way undergirds the rest of his writings, including the present volume, is Kantian and Neoplatonic. By his lights, it is simply impossible for a thinker to evade the “problem of being,” and yet one may never assume that “being is something generally understood.” With Kant, he repeatedly asserts the validity of the thesis that everything “objective” is always conditioned by “consciousness,” and thus he regards any claim about purely objective being (in his vocabulary, Dasein) as invariably an illusion.
Yet we live in the reality of the life-world, and so we do well to accept the Neoplatonic heritage of diverse spheres of being that philosophical reflection can progressively distinguish. There is a triad of levels of existence to be noticed: (1) the simple givenness of “objects” whenever individuals encounter anything real in their normal experience; (2) the human constructions of the life-world of the subject (internally within an individual and externally, for instance, in the trust-relations that constitute communities large and small); and (3) transcendent being that is always in principle beyond what any subject-mind can ever mentally encompass but to which the symbols devised by religion and philosophy regularly venture to point. Again, with Kant, Jaspers articulates a doctrine of Ideas that places him squarely in the tradition of German Idealism, yet always in a way that is tempered by the basic realism of Jaspers’s own medical and political heritage.
The result is that he is the sort of philosopher who can help “realists” learn what they need to discover from “idealism” and vice versa.5 More specifically, Jaspers amplifies Kant’s basic doctrine of the three Ideas (the world, the soul, and God) that reason must postulate in order to compensate for the fact that we are never presented with the whole of reality and yet we constantly feel the hunger to think about such wholes. We human beings know anything that we do come to know only within the boundaries of some horizon or other. Here Jaspers’s point is much like both that of Aristotle, who long before insisted that we know an object only by grasping its form or structure, and that of the long tradition of realism, which has regularly identified an object’s form with transcendental truth, the fundamental intelligibility of every being as being.6 But thinking this problem through as a Kantian committed to the doctrine that there is “no object without a subject” and thus no access to objectivity that is not categorically conditioned by consciousness and its attendant subjectivity, Jaspers proposes that “the world” (cosmos) is the Idea that we project in order to encompass all possible objective viewpoints, even though such a whole is actually unknowable to us in principle. Likewise, the depths of consciousness that are the ground for the second level of existence are never able to be fully plumbed by anyone, and so they are equally unknowable as a whole, and yet we need some way of thinking about them. So, according to Jaspers, following Kant, reason offers the I, the soul, as a useful mode of encompassing consciousness. At the third level, God or Transcendence is the Idea by which to encompass all of being, but the reality of such being is as ineffable as the One envisioned by Plotinus.