Radical

From Philosopedia

RADICAL

Radical, a word the Latin root of which (radix) means root, is used by many conservatives to depict some kind of scary revolutionary whose nihilism might include blowing up buildings — if an idea is different from the usual, to them it is radical.

Radical, however, is used by rationalists to describe going to the root of a problem; e.g., “Choose the radical solution of starting all over again.”

Radix is the root of radish, a plant the roots of which are preferred by diners over the upper portions.

Rationalists, those known for going to the roots of problems, can rightfully be called radicals, individuals who prefer going to primary sources rather than simply accepting what appears on the surface.