Born in Tientsin, China, to missionary parents Henry and Elizabeth Porter, Porter graduated from Beloit College (1901) and Yale Divinity School (1906). He also studied at Berlin, Marburg, Jerusalem, and Union Theological Seminary (New York), and received the M.A. at Columbia University in 1916. He married Lillian Lee Dudley in 1908. Under the appointment of the American Board of Commissioners for Foreign Missions (ABCFM) he taught at North China Union College, Tungxian, until 1918, also serving as general secretary of the North China Kung Li Hui from 1917 to 1919.
With the establishment of Yenching University in Beijing, Porter served as dean from 1918 to 1922 and began his many years of service as professor of philosophy (until 1949). For various periods he also served as executive secretary of the Harvard-Yenching institute and taught at the Beijing School of Chinese Studies. During the Japan occupation he taught at the refugee university in Sichuan Province in 1935 and took charge of the ABCFM properties in Shansi from 1937 to 1939. Interned in 1943, he refused repatriation in order to be on hand when Yenching was restored. Porter was visiting lecturer at Columbia (1924), Harvard (1928-1929, 1931-1932), Claremont (1938), and Beloit (1940-1941), and held honorary degrees from Beloit (D.D.) and New York University (L.H.D.).
He was active in dramatics at Yenching and author of China's challenge to Christianity (1924) and Aids to the Study of Chinese Philosophy (1934). His grandfather Jeremiah Porter, was the first Congregational pastor in Chicago; his maternal grandfather, Aaron Chapin, was the first president of Beloit College. His sister, Mary H. Porter, was the first missionary of the Congregational Women's Board of Missions of the Interior; she also served in China.