Henry becomes increasingly interested in contemporary methods of science, foreshadowing his later attempts to apply scientific method to the study of history. The works of two Englishmen are especially important to Henry at this point in his education. Naturalist Charles Robert Darwin has recently (1859) published his seminal work, On the Origin of Species, arguing for a theory of evolution. Geologist Sir Charles Lyell, a friend of Darwin, a frequent visitor to the Legation, and eventually a friend of Henry's, has supported Darwin's theory in his Antiquity of Man (1863) and the tenth edition of his Principles of Geology (1866). Henry is somewhat skeptical of evolution but influenced by the scientific approach.
The significance of Darwin and Lyell in the story of Henry's education is that they are early influences in his burgeoning enthusiasm for scientific method. As Ernest Samuels points out in The Young Henry Adams, "It is hard to exaggerate the stir caused by the scientific discoveries of the mid-century." Darwin, especially, was front-page news. Influenced early by Lyell and in turn influencing the geologist's work, Darwin proposes that plants and animals develop from earlier forms through hereditary transmissions of slight differences; a process of natural selection determines which will survive. He proposes that species themselves actually change through evolution. For example, individuals in a given generation may have a variation in their physical makeup that gives them an advantage in their environment. If their food source is in a tree, their toes may allow them to climb slightly better; or their necks or legs may be longer; or they may be able to shake the food loose better. Individuals with these characteristics are more likely to survive and reproduce. In this way, the species may evolve. Darwin's theory of evolution poses a direct threat to fundamentalist interpretations of the Bible — Genesis, for example — and this is news in the 1860s. As one reviewer says of Darwin's work, "Old ladies of both sexes consider it a decidedly dangerous book."
Lyell also bothers fundamentalists by showing geological evidence of man's development of the use of tools, for example, over a long period of time. Darwin's theories are consistent with Lyell's discoveries, and Lyell follows him in supporting evolution. Both negate the likelihood of a sudden event of Creation. Lyell further maintains that changes in the earth's surface can best be explained by continuing causes — not by primeval geological catastrophes as formerly believed. So both argue that there is a process in the development of the earth and its inhabitants.
Portions of these theories have been refined, reconsidered, and even discarded over time. The importance for Henry Adams is that they start him thinking about history in terms of scientific approach. Could the developmental patterns of a society, for example, be understood in the way that Darwin explains evolution? Could a scientist's method of measuring the gradual augmentation and diffusion of heat or the dissipation of energy apply to historical cycles? Could there be a workable dynamic theory of history? Later in life, and later in the Education, Adams attempts to espouse just such a theory.
vestige a trace, mark, or sign of something that once existed but has disappeared.
a posteriori (Latin) from effect to cause; based on observation rather than theory.
intelligible clear, comprehensible, understandable.
Pteraspis the first vertebrate, according to Lyell; a fish, existing 400 million years ago, related to the sturgeon, used by Adams as a symbol of sequence and continuity throughout the Education.
audacity bold courage, daring.