Klages was born in Hanover, Germany. In Munich he studied physics, philosophy and chemistry - however, after completing his doctorate in chemistry he resolved never to work as a chemist. He met the sculptor Hans Busse and with him and Georg Meyer he founded the Deutsche Graphologische Gesellschaft (German Graphology Association) in 1894.
In Munich Klages also encountered the writer Karl Wolfskehl and the mystic Alfred Schuler. He was a lover of Fanny zu Reventlow, the "Bohemian Countess" of Schwabing, and with Wolfskehl, Schuler and the writer Ludwig Derleth they formed a group known as the Munich Cosmic Circle, with which the poet Stefan George is sometimes associated. He wrote a book praising George's poetry in 1902. As a member of this group his philosophy contrasted the "degenerate" modern world with an ancient, and mystical, Germanic past, with a heroic role for the artist in forging a new future. George distanced himself from Klages' mystical philosophy (which was shared by Schuler), but continued for a time to publish Klages' poems in his journal Blätter für die Kunst. Wolfskehl acquainted Klages with the work of Johann Jakob Bachofen (1815-1887), a Swiss anthropologist and sociologist, and his research into matriarchal clans.
In 1914 at the outbreak of war Klages moved to Switzerland and supported himself with his writing and income from lectures. He returned to Germany in the 1920s and in 1932 was awarded the Goethe medal for Art and Science. However by 1936 he was under attack from National Socialist authorities for lack of support and on his 70th birthday in 1942 was denounced by many newspapers in Germany. After the war he was honoured by the new government, particularly on his 80th birthday in 1952.
Basic Theory of Life
Ludwig Klages held that all humans (as well as animals, plants, etc.) have souls (Seele), of which the body or physical form is an image, and that the body and soul were originally a unity (he rejected the Christian view of the division of body and soul, accepting instead the Greek tripartite division of body, soul, and spirit). According to Klages, in primordial or pre-historic times, humanity lived in "ecstatic, image-laden, and rhythmically pulsating life" (Rosenberg's description), and was thus living in accordance with the principle of Life. However, eventually a force that Klages refers to as Spirit (Geist) intruded into human life, damaging the harmonious unity of body and soul (seele) and ruining man's life. Spirit caused humans to move towards critical and rational thought, thus causing them to become cultured and, in later phases of civilization, mechanized in their living, thus corrupting life. In Klages's "biocentric metaphysics," the term Soul (Seele) refers to a metaphysical entity united with the body, producing pure life and Feeling, while Spirit (Geist) refers to another metaphysical force which produces reason, will, and intellect. Thus, according to Klagesian thought, any such form of thought as rationalism, formalistic and mechanistic thought, technological and mathematical development, etc. are products of the Spirit, interfering and limiting mankind's life. Klages held that the more we move through history the more Spirit takes over human existence, eventually culminating in a soulless man who destroys the natural world (by his overconsumption of natural resources) and finally dies off. It can be speculated that after this apocalyptic event a new life cycle will begin with Spirit no longer dominant.
This theory which Klages held could be criticized from many standpoints (although it does not necessarily have to be rejected in toto), as was done by Alfred Baeumler and Alfred Rosenberg. Rosenberg stated in The Myth of the Twentieth Century that he agreed with Klages on the point that over-intellectualism and rationalism destroyed organic culture and also caused race-mixing. But he also pointed out that these facts do not provide adequate grounds to reject rational thought and intellect as evil (which Klages blames on "Spirit"). In fact, Rosenberg pointed out, people should have a balance between soul or life and will and reason; there is no need to go to the extreme conclusions to which Klages went. Man should neither be totally primitive nor should he be totally civilized and mechanized; pure life is enhanced by a moderate use of the intellect. Klages himself admitted that there were situations in which spirit and soul had a harmonious balance that was not necessarily damaging to Life; what we are suggesting is that this balanced existence is the one that is what is ideal for human life, whereas Klages views unconscious life as the ideal. A final interesting point Rosenberg made was: "And one fact here seems to us to be quite curious, because we cannot avoid the impression that these embittered warriors against the life-alien rationalism of modernity have concocted their instinctively creative and heroic primitives—in what seems to us to be a completely rational manner."
He created a complete theory of graphology and will be long associated with the concepts of form level, rhythm and bi-polar interpretation. He is important because together with Nietzsche and Bergson he anticipated existential phenomenology. He also coined the term logocentrism in the 1920s.
He was the author of 14 books and 60 articles (1910-1948). He was co-editor of the journals Berichte (1897-8) and its successor Graphologische Monatshefte until 1908. His most important works are:
- Der Geist als Widersacher der Seele (1929)
- Die Grundlagen der Charakterkunde
When Klages died, the German philosopher Jürgen Habermas urged that Klages' "realizations concerning anthropology and philosophy of language" should not be left "hidden behind the veil" of Klages' "anti-intellectualist metaphysics and apocalyptic philosophy of history". Habermas characterized these realizations as "not outdated" but ahead of the time.
- Prinzipien der Charakterologie (1910, seit 1926 Die Grundlagen der Charakterkunde. 14. Aufl.). Bouvier, Bonn 1969.
- Mensch und Erde (1913; mit anderen Abhandlungen 5. Aufl.) Diederichs, Jena 1937.
- Ausdrucksbewegung und Gestaltungskraft. (1913; später Grundlegung der Wissenschaft vom Ausdruck. 7. Aufl. Engelmann, Leipzig 1950).
- Handschrift und Charakter. Gemeinverständlicher Abriß der graphologischen Technik. (1917; 29. Aufl. für die Deutungspraxis bearbeitet und ergänzt von Bernhard Wittlich.) Bouvier, Bonn 1989, ISBN 3-416003-12-8.
- Vom Kosmogonischen Eros (1922; zitiert nach 9. Aufl.) Bouvier, Bonn 1988, ISBN 3-416-00272-5.
- Die psychologischen Errungenschaften Nietzsches. Barth, Leipzig 1926.
- Zur Ausdruckslehre und Charakterkunde. Gesammelte Abhandlungen. N. Kampmann, Heidelberg 1926 
- Der Geist als Widersacher der Seele (1929–32, Hauptwerk in 3 Bänden). 5. Aufl. Bouvier, Bonn 1972.
- Vom Wesen des Rhythmus. Kampmann, Kampen auf Sylt 1934.
- Die Sprache als Quell der Seelenkunde. Hirzel, Zürich 1948.
- Ludwig Klages und Ernst Frauchiger (Hrsg.): Ludwig Klages. Sämtliche Werke. 16 Bände. Bouvier, Bonn 1964–1996.
- Ludwig Klages, The Biocentric Worldview, tanslated & introduced by Joseph Pryce, London: Arktos, 2013.
- Gunnar Alksnis, Ludwig Klages and His Attack on Rationalism (Kansas State University, 1970).
- Steven E. Aschheim, The Nietzsche Legacy in Germany, 1890-1990 (Los Angeles: University of California Press, 1994).
- Reinhard Falter: Ludwig Klages. Lebensphilosophie als Zivilisationskritik (Munich: Telesma, 2003), ISBN 3-833-0678-1
- Michael Golston, Rhythm and Race in Modernist Poetry and Science: Pound, Yeats, Williams, and Modern Sciences of Rhythm (Columbia University Press, 2013).
- Richard T. Gray, About Face: German Physiognomic Thought from Lavater to Auschwitz (Detroit: Wayne State University Press, 2004).
- Nitzan Lebovic, The Philosophy of Life and Death: Ludwig Klages and the Rise of a Nazi Biopolitics (New York: Palgrave Macmillan, 2013).
- Nitzan Lebovic, The Politicization of Lebensphilosophie: From Ludwig Klages to National Socialism (1870-1933) (Los Angeles: University of California, 2005 ).
- Nitzan Lebovic, "The Terror and Beauty of Lebensphilosophie: Ludwig Klages, Walter Benjamin, and Alfred Bauemler", South Central Review 23:1 (Spring 2006), pp. 23- 39.
- James Lewin: Geist und Seele: Ludwig Klages’ Philosophie, (Berlin: Reuther & Reichard, 1931)
- Anthony Phelan, The Weimar Dilemma: Intellectuals in the Weimar Republic (Manchester University Press, 1985).
- Marion E. P. de Ras, Body, Femininity and Nationalism: Girls in the German Youth Movement 1900–1934 (New York & Milton Park: Routledge, 2008).
- Alfred Rosenberg, The Myth of the Twentieth Century. Sussex, England: Historical Review Press, 2004.
- Alfred Rosenberg, Gestalt und Leben, delivered on April 27, 1938, inaugurating the University of Halle’s Summer Semester. <Available at "Rosenberg contra Klages">
- Herbert Schnädelbach, Philosophy in Germany, 1831-1933. Cambridge: Cambridge University Press, 1984.
- Tobias Schneider, "Ideological Trench Warfare. Ludwig Klages and National Socialism from 1933-1938." Vierteljahrshefte für Zeitgeschichte 2/2001 (http://www.ifz-muenchen.de/heft2_2001.html?&L=30)
- Oliver A.I. Botar and Isabel Wünsche, eds., Biocentrism and Modernism, Farnham, Surrey, England: Ashgate Publishing, Ltd., 2011.
- Lydia Baer, "The Literary Criticism of Ludwig Klages and the Klages School: An Introduction to Biocentric Thought." The Journal of English and Germanic Philology Vol. 40, No. 1 (Jan., 1941), pp. 91-138.
- Peter J. Davies, Myth, Matriarchy and Modernity: Johann Jakob Bachofen in German Culture, 1860-1945 (Walter de Gruyter, 2010).
- Gerd-Klaus Kaltenbrunner, Der schwierige Konservatismus (Berlin: Nicolaische Verlagsbuchhandlung, 1975).
- Gerd-Klaus Kaltenbrunner, Ludwig Klages oder Vom Weltschmerz des technischen Zeitalters (München: Verlag gestern und heute, 1967).
- Joe Pryce, “On The Biocentric Metaphysics of Ludwig Klages,” Revilo-Oliver.com, 2001, <http://www.revilo-oliver.com/Writers/Klages/Ludwig_Klages.html>.
- Marja Väätäinen, "From Ringbom to Ringbom" The art of art history of Lars-Ivar Ringbom and Sixten Ringbom," Journal of Art Historiography, Number 7 (December 2012). <http://arthistoriography.files.wordpress.com/2012/12/vaatain.pdf>.
- "The Biocentric Metaphysics of Ludwig Klages" by Joe Pryce (An Introduction to Klages with other pages containing translated excerpts from Klages's works)
- The Science of Character
- Cosmogonic Reflections by Ludwig Klages at the Internet Archive
- File of "On the Biocentric Metaphysics of Ludwig Klages" at the Internet Archive
- "The Literary Criticism of Ludwig Klages and the Klages School" by Lydia Baer at the Internet Archive
- "Ludwig Klages on Judaism, Christianity and Paganism"
- "From Ringbom to Ringbom" by Marja Väätäinen