Charles Hartshorne (June 5, 1897 – October 9, 2000) was a prominent American philosopher who concentrated primarily on the philosophy of religion and metaphysics. He developed the neoclassical idea of God and produced a modal proof of the existence of God that was a development of St. Anselm's Ontological Argument. Hartshorne is also noted for developing Alfred North Whitehead's process philosophy into process theology.

Hartshorne (pronounced harts-horn) was born in Kittanning, Pennsylvania, and was the son of Reverend F.C. Hartshorne. Among his brothers was the prominent geographer Richard Hartshorne. Charles attended Haverford College between 1915–17, but then spent two years as a hospital orderly serving in the US Army. He then studied at Harvard University, where he earned the B.A. (1921), M.A. (1922) and PhD (1923) degrees. His doctoral dissertation was on "The Unity of Being". He obtained all three degrees in only four years, an accomplishment believed unique in Harvard's long history.

Alfred North Whitehead, OM FRS (15 February 1861 – 30 December 1947) was an English mathematician who became a philosopher. He wrote on algebra, logic, foundations of mathematics, philosophy of science, physics, metaphysics, and education. Whitehead supervised the doctoral dissertations of Bertrand Russell and Willard Van Orman Quine, thus influencing logic and virtually all of analytic philosophy. He co-authored the epochal Principia Mathematica with Russell.

Whitehead was born in Ramsgate, Kent, England. Although his grandfather, Thomas Whitehead, was known for having founded Chatham House Academy, a fairly successful school for boys, Alfred North was educated at Sherborne School, Dorset, then considered the best public school in the country. His childhood was described as over-protected, but when at school he excelled in sports, mathematics and was head prefect of his class.

In 1880, Whitehead matriculated at Trinity College, Cambridge, where he was fourth wrangler and gained his BA in 1884. Elected a fellow of Trinity in 1884, Whitehead would teach and write mathematics at the college until 1910, spending the 1890s writing his Treatise on Universal Algebra (1898), and the 1900s collaborating with his former pupil, Russell, on the first edition of Principia Mathematica.