Princeton University professor and world-renowned Australian philosopher Frank Jackson spoke to The University of Alabama on Oct. 30 about the theory of physicalism as a part of the Philosophy Today lecture series.

The Philosophy Today series is a five-year program created by the philosophy department that invites four modern philosophers to lecture to people within and outside the field of philosophy.

Jackson’s lecture titled “The Problem of Consciousness” explores the idea of physicalism through the experience of color. Physicalism is the idea that an object is nothing besides its physical properties. During his lecture, Jackson described physicalism using the examples of the “No Freedom Room” and the “No Color Room.”

Torin Alter, a philosophy professor, introduced the speaker, describing Jackson as his “philosophical hero” and saying his own work “is just footnotes to Frank Jackson’s work.”

“[Jackson is] one of the foremost professors in the philosophy of the mind today,” Joshua Quick, a graduate student studying applied statistics, said.

Although Jackson promotes physicalism now, it wasn’t always that way.

Jackson once created the “Mary’s Room” theory that went against physicalism and argued that non-physical knowledge can be obtained through consciousness. He believed that if a scientist understood the scientific concepts behind the color red but was only ever exposed to black and white, she would still learn when finally exposed to red.

“Jackson’s theory appeased some arguments for dualists, so it became their go-to argument,” Josh Gravlee, a senior majoring in philosophy, said.

After changing his philosophical ideals from dualism to physicalism, Jackson crumbled the main argument of dualists.

“Most philosophers are headstrong, but changing of opinions do h