Carus (Latin: Marcus Aurelius Carus Augustus; c. 224 – July or August 283), was Roman Emperor from 282 to 283. During his short reign, Carus fought the Germanic tribes and Sarmatians along the Danube frontier with success. During his campaign against the Sassanid Empire he sacked their capital Ctesiphon, but died shortly thereafter. He was succeeded by his sons Carinus and Numerian; creating a dynasty which, though short-lived, granted further stability to a resurgent empire.

Carus, whose name before the accession may have been Marcus Numerius Carus, was born, probably, at Narbo (modern Narbonne) in Gaul, but was educated at Rome. He was a senator, and had filled various civil and military posts before he was appointed prefect of the Praetorian Guard by the emperor Probus in 282. After the murder of Probus at Sirmium, Carus was proclaimed emperor by the soldiers. Although Carus severely avenged the death of Probus, he was himself suspected of having been an accessory to the deed. He does not seem to have returned to Rome after his accession, but contented himself with an announcement of the fact to the Senate.

Carl Gustav Carus (3 January 1789 – 28 July 1869) was a German physiologist and painter, born at Leipzig. A friend of Johann Wolfgang von Goethe, he was a many-sided man: a doctor, a naturalist, a scientist and a psychologist and an advocate of the theory that health of body and mind depends on the equipoise of antagonistic principles. A landscape painter, he had drawing lessons from Julius Diez and subsequently studied under Julius Schnorr von Carolsfeld at the Oeser drawing academy. From 1814 to 1817 he taught himself oil painting working under Caspar David Friedrich, a Dresden landscape painter.

In 1811 he graduated as a doctor of medicine and a doctor of philosophy. In 1814 he was appointed professor of obstetrics and director of the maternity clinic at the teaching institution for medicine and surgery in Dresden. He wrote on art theory.

He is best known to scientists for originating the concept of the vertebrate archetype, a seminal idea in the development of Darwin's theory of evolution. In 1836, he was elected a foreign member of the Royal Swedish Academy of Sciences. Carus is also noted for Psyche (1846).

Paul Carus, Ph.D. (18 July 1852 – 11 February 1919) was a German-American author, editor, a student of comparative religion, and professor of philosophy.

Carus was born at Ilsenburg, Germany, and educated at the universities of Strassburg, France and Tübingen, Germany. After obtaining his Ph.D. from Tübingen in 1876 he served in the army and then taught school. He had been raised in a pious and orthodox Protestant home, but gradually moved away from this tradition.

He left Bismarck's Germany for the United States, "because of his liberal views". After he immigrated to the USA (in 1884) he lived in Chicago, and in LaSalle, Illinois. Paul Carus married Edward C. Hegeler's daughter Mary (Marie) and the couple later moved into the Hegeler Carus Mansion, built by her father. They had six children.

In the United States, Carus briefly edited a German-language journal and wrote several articles for the Index, the Free Religious Association organ.

Soon after, he became the first managing editor of the Open Court Publishing Company, founded in 1887 by his father-in-law. The goals of Open Court were to provide a forum for the discussion of philosophy, science, and religion, and to make philosophical classics widely available by making them affordable.