English mathematician and physicist. Precursor of Einstein's General Theory of Relativity and originator of what are now known as Clifford algebras.

Originator of what is known as Clifford's dictum: "It is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence". This is explained in his excellent "The Ethics of Belief", that concerns the conditions human beliefs of any kind must satisfy in order to be fairly called rational.