Christine Ladd-Franklin

Christine Ladd-Franklin (December 1, 1847 – March 5, 1930) was an American psychologist and logician.

Christine Ladd-Franklin was born in Windsor, Connecticut to Eliphalet Ladd and Augusta Niles. In 1869 she graduated from the newly opened Vassar College, where she studied linguistics and physics. After graduation, as women were not granted much access to labs and observatories, she turned to mathematics, which did not require any apparatus. For instance, in 1877 she published a synopsis of trigonometric identities expressed in the notation of quaternions. She taught science and mathematics in Washington, Pennsylvania at the secondary level until 1878, while also contributing several articles on mathematics to the Educational Times of Great Britain.

With the help of James Joseph Sylvester, Ladd was able to enroll for graduate study at Johns Hopkins University in 1878. She wrote a dissertation "On the Algebra of Logic" with Charles Sanders Peirce as the thesis advisor and in 1882 she earned a Ph.D. in logic and mathematics. The dissertation was published in Studies in Logic (Peirce, ed.) in 1883. However, the Ph.D. was awarded to her only decades later, in 1926. She was Associate Editor for Logic and Psychology and Contributor for Logic for Baldwin's Dictionary of Philosophy and Psychology published 1901-1905 (her contributions appear with the initials "C.L.F.").

On August 24, 1882, she married Fabian Franklin, a Johns Hopkins mathematics professor. They had two children, a son who lived only a few days and a daughter Margaret Ladd Franklin who grew up and became a prominent member of the women's suffrage movement. Christine herself helped many women participate in graduate education.

Ladd-Franklin was interested in vision, particularly color vision, and in 1929 she published Color and Color Theories.

In 1948, Bertrand Russell wrote: "I once received a letter from an eminent logician, Mrs. Christine Ladd-Franklin, saying that she was a solipsist, and was surprised that there were no others. Coming from a logician and a solipsist, her surprise surprised me." (Russell, p. 180).

She died in New York City.

Published works

 * "Quaternions", The Analyst v. 4, n. 6, pp. 172–4 (Nov 1877). Google Books The Analyst p. 172 in n. 6 (November) in v. 4 (1877). Also JSTOR "Quaternons" first page. (Several journals have been called "The Analyst". See The Analyst (disambiguation). Internet searches for The Analyst, the one which became The Annals of Mathematics, should use the search phrase "The Analyst" mathematics, otherwise The Analyst about chemistry will dominate search results.)
 * "On the Algebra of Logic" in Studies in Logic, C. S. Peirce, ed., pp. 17–71, 1883. Google Books Eprint. Internet Archive Eprint.
 * "On Some Characteristics of Symbolic Logic" in the American Journal of Psychology, v. 2, n. 4, pp. 543–567, August 1889. Google Books Eprint. Internet Archive Eprint.
 * "Epistemology for the logician" in  Verhandlungen des III. Interntionalen Kongresses fur Philosophie. , pp. 664–670, 1908. Also separately as an offprint.
 * "Charles Peirce at the Johns Hopkins", The Journal of Philosophy, Psychology, and Scientific Methods v. 13, n. 26, 715–723, December 1916. Google Books Eprint (badly done) and seek the text.
 * "The Reddish Blue Arcs and the Reddish Blue Glow of the Retina; an Emanation from Stimulated Nerve Fibre." in  VIIIth International Congress of Psychology: Proceedings and Papers, 1926.
 * Colour and Colour Theories, Routledge, 320 pages, 1929.