”Extremism” is a term which, standing by itself, has no meaning. The concept of “extreme” denotes a relation, a measurement, a degree. The dictionary gives the following definitions: “Extreme, adj.—1. of a character or kind farthest removed from the ordinary or average. 2. utmost or exceedingly great in degree.”

It is obvious that the first question one has to ask, before using that term, is: a degree—of what?

To answer: “Of anything!” and to proclaim that any extreme is evil because it is an extreme—to hold the degree of a characteristic, regardless of its nature, as evil—is an absurdity (any garbled Aristotelianism to the contrary notwithstanding). Measurements, as such, have no value-significance—and acquire it only from the nature of that which is being measured.

Are an extreme of health and an extreme of disease equally undesirable? Are extreme intelligence and extreme stupidity—both equally far removed “from the ordinary or average”—equally unworthy? Are extreme honesty and extreme dishonesty equally immoral? Are a man of extreme virtue and a man of extreme depravity equally evil?

- Ayn Rand. Capitalism: The Unknown Ideal (1966).