He also developed the concept of accountability for reasonableness with James Sabin, an ethics framework used to challenge the healthcare resource allocation in the 1990s.

Previously, and for 33 years, he had taught political philosophy at Tufts University in Medford, Massachusetts.

[9] They have one son, Noah M. Daniels (Ph.D), currently an Associate Professor in the Department of Computer Science and Statistics of The University of Rhode Island.

[10] With Jared Israel, Daniels co-chaired the Harvard chapter of the Students for a Democratic Society in 1969.

[11][12][13] In a public letter to his fraternity brothers at Wesleyan, Daniels wrote: "At Harvard, I ended up co-chair of SDS and gave the speech on the steps of University Hall April 9, 1969, that began the take-over of that administration building and thus led to the Harvard Strike.