Jean Baptiste Lamarck, an important figure in the development of pre-Darwinian evolutionary theory, exerted considerable influence on American writers prior to Charles Darwin's Origin of Species (1859). Ralph Waldo Emerson, for example, in his Journals, mentions Lamarck with respect. The fact that Walt Whitman was clearly an evolutionist in the first edition of Leaves of Grass, published four years before Darwin's work, prompts some scholars to point to Lamarck's influence on Whitman's evolutionary thought. It is important to remember that the phrenologists (influential for the early Whitman) knew of Lamarck's work and applied it regularly in their practice. A study of Whitman's Lamarckianism would likely link him to writers like Friedrich Nietzsche (the Superman theory), Thomas Carlyle, Henri Bergson, George Bernard Shaw, and others. The writings of Herbert Spencer (1820–1903) made Lamarck's views popularly known during the nineteenth century.
Lamarck believed that complex organisms were developed from pre-existent simpler forms, and based his theories on four "laws": (1) Life by its proper forces tends continually to increase the volume of every body possessing it, and to enlarge its parts up to a limit which it brings about; (2) The production of a new organ in an animal body results from a supervention of a new want continuing to make itself felt, and a new movement which this want gives birth to and encourages; (3) The development of organs and their force of action are constantly in ratio to the employment of these organs; (4) All which has been acquired, laid down, or changed in the organization of individuals in the course of their life is conserved by generation and transmitted to the new individuals that proceed from those which have undergone these changes.
Readers of Leaves of Grass will readily see that Lamarckianism fits Whitman's moral and spiritual scheme admirably. For Whitman, man himself reflects the dominant manifestation of the life-force; man is therefore always imperfect, yet forever striving for perfection; society, made up of men, is imperfect, yet forever climbing toward a perfect state; all the universe is a growing organism, proceeding from all that preceded it and contributing to all that will follow it; all life is made of the same stuff and is continually propelled to higher momentum, compelled to move and change; all forms of life are in communion with one another; man, as leader of the process of becoming, must exercise his imagination, conceive new wants, and guard his freedom, which—although it ascribes harsher and harsher responsibilities—is the prerequisite to progress. In the social realm, Lamarckianism promises that what one generation struggles for and achieves may be transmitted to the next generation and all others which follow it.
Bibliography
Allen, Gay Wilson. The Solitary Singer: A Critical Biography of Walt Whitman. 1955. Rev. ed. 1967. Chicago: U of Chicago P, 1985.
Aspiz, Harold. Walt Whitman and the Body Beautiful. Urbana: U of Illinois P, 1980.
Beaver, Joseph. Walt Whitman: Poet of Science. Morningside Heights, N.Y.: King's Crown, 1951.
Conner, Frederick William. Cosmic Optimism: A Study of the Interpretation of Evolution by American Poets. Gainesville: U of Florida P, 1949.
Reynolds, David S. Walt Whitman's America: A Cultural Biography. New York: Knopf, 1995.
Tanner, James T.F. "The Lamarckian Theory of Progress in Leaves of Grass." Walt Whitman Review 9 (1963): 3–11.