Radical. Generally, when we hear this word today, it’s being used to describe political or other views and positions. It means, in that sense, “extreme.” And because it’s used like that so often, we tend to think of it that way still when we hear phrases like “radical surgery” or “a radical mastectomy.” Wow, we might think, that must be quite an extreme surgery!
And it may be…but in fact, that use of radical is very much secondary, and it isn’t at all what’s meant in the scientific, mathematical, or medical communities when they use the word. Because, you see, radical actually means “pertaining to the roots or origins” or even “vital to life.” Radical is from the Latin radix, which literally just means “roots.”
For hundreds or even thousands of years, radical was used very literally, and it’s still used literally in the scientific and mathematical communities. But it began to take on figurative meaning in the 1650s, at which point it meant “going back to the origin, essential.”
How, then, did it come to mean an extreme? That’s an interesting journey! In the early 1800s, politicians began to use the word to describe “reformists”…those who claimed to be trying to restore a political party (or religious group) back to its origins. But along the way “reformist” just came to mean any sort of change…and then, eventually, extreme change.
Which of course means that radical has the distinction of being one of those few words that can be the opposite of itself, meaning both “the original position” and “the extreme position.” Who knew that the etymology of radical could be so radical?! (The surfer slang came around in the 1970s, meaning “at the limits of control,” and became popularized in the 80s.)