In Franklin's Footsteps: 275 Years at the American Philosophical Society (Online Exhibition)

Part 2: Let Light into the Nature of Things

In the 19th century, many Members responded to Franklin’s call to “let light into the nature of things.” They documented the natural world, questioned the origins of man, and studied different cultures.

Charles Darwin’s (APS 1869) groundbreaking ideas about natural selection and evolution resulted in the emergence of new and increasingly specialized fields. Geologists and paleontologists sought to prove Darwin’s theories by examining rocks and fossils as physical evidence of evolutionary change. Anthropologists similarly studied language and culture to better understand people in both the past and present.

Many of the biggest debates of the day took place at the APS. The Society created connections among paleontologists, geologists, and anthropologists, who presented their work at APS Meetings or in APS publications like the Transactions and Proceedings.

Charles Darwin and the Origin of Species

Charles Darwin transformed scientific thought with the publication of On the Origin of Species. His theory of evolution through natural selection became the basis of modern biology. Darwin’s ideas are fundamental to our understanding of the history of life on Earth.

The APS has the largest collection of Darwin manuscripts in North America. The APS is also one of the largest repositories of Darwin publications in the world, with many first editions of Darwin’s 19 books and translations of On the Origin of Species in 23 languages.

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What Lies Beneath: Geology

Darwin’s ideas about evolution were influenced by geologist Charles Lyell, who argued that the surface of the earth changed slowly but continuously. After the publication of On the Origin of Species, scientists increasingly looked to rocks for evidence about the age of the earth and how the planet has changed over time.

In the late 19th century, geological surveys became useful for locating oil, coal, and gas resources. Influential geologist J. Peter Lesley (APS 1856) directed the Second Pennsylvania Geological Survey (1874–1889). Lesley published many geographical reports in APS publications, and also served as APS Librarian, Secretary, and Vice President.

A Geological Hand Atlas of the Sixty-Seven Counties of Pennsylvania

J. Peter Lesley, 1885

Geological Survey

Benjamin Smith Lyman, 1863

Topographical Map of Pennsylvania

J. Peter Lesley, 1874–1876

Letter to Charles Henry Moore

Charles Lyell, 1866

What Lies Beneath: Paleontology

Evidence for Darwin’s theories were not found in living species alone. Paleontologists studied the fossils of ancient creatures for evidence of evolution. Fossils like Megalonyx jeffersonii, Hadrosaurus foulkii, and Elasmosaurus platyurus showed how some species changed or died out over time.

Research published in the APS Transactions and APS Proceedings stimulated spirited debate in the new fields of paleontology and geology. One volume of the APS Transactions even initiated a bitter rivalry between leading paleontologists that came to be known as the “Bone Wars.”

Megalonyx jeffersonii Hand Bones

Species named by Thomas Jefferson and Anselme-Gaëtan Desmarest, 1797 and 1822

Letter to John Stuart

Thomas Jefferson, 1796

Hadrosaurus foulkii toe

Species named by Joseph Leidy, 1858

Letter to Joseph Leidy

William Parker Foulke, 1858

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Article published in APS Transactions (Vol. 14)

E. D. Cope, 1870

Elasmosaurus Snout

Species named by E. D. Cope, 1868

Letter to J. P. Lesley

E. D. Cope, 1872

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Philip Gingerich (APS 2010)

The Study of Man

Anthropology is the study of humans in society, both past and present. In the late 1800s, Franz Boas (APS 1903) shaped the field of modern anthropology by challenging widespread beliefs in a cultural hierarchy.

Boas mentored a number of exceptional female anthropologists. He recognized their contributions when many learned societies, including the APS, did not. Many of Boas’s students donated their papers to the Society’s extensive anthropology collections.

Today, the APS Library’s Center for Native American and Indigenous Research (CNAIR) continues Boas’s mission. CNAIR works with community-based scholars, knowledge keepers, and tribal organizations to reconnect archival collections to communities.

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Anthropometric data sheets

Franz Boas, 1892

handwritten page from Boas's field notebook

Fieldwork Notebook

Franz Boas, 1886

handwritten page from Mary Haas's field notebook

Fieldwork Notebook

Mary Haas, 1936

The Florida Expedition

Zora Neale Hurston, c. 1937

Letter to Franz Boas

Ruth Benedict, 1940

The Eugenics Movement

Darwin’s ideas transformed scientific thought in many positive ways. However, some scientists—including prominent APS Members—extended Darwin’s theories to human society to justify racism, imperialism, and xenophobia. These beliefs produced the eugenics movement in the early 20th century.

Eugenicists believed that controlling human reproduction would improve society. They discriminated against physical, mental, and emotional conditions as well as certain racial and ethnic groups. Their efforts had harmful consequences for America and the world, promoting hateful policies and intolerance.

Today, scholars use the APS Library’s extensive eugenics collections to shed light on this dark history.