As David Robins reminds us in the current issue, the "cult of cool" has become the dominant ethic among young people in developed countries. If so (and Robins may be right, even if he overestimates the connection between the "cool" mentality and knife crime), it is an interesting example of the power of language: of how a mere word, and one with an incredibly vague meaning, can give rise to an ethos to which millions subscribe.
Linguists are uncertain when the word "cool," in its modern sense, originated. Clearly, the basic idea is metaphorical. Behaving in a "cool" way is the opposite of behaving in a "hot" way: it signifies calmness and detachment as against emotionalism and impulsiveness. This idea of coolness remains part of the word's meaning—Clint Eastwood is "cool" because of his impassivity. But at a certain point cool acquired a secondary, overlapping sense: it came to signify something exciting, stylish or fun. The attribute of coolness was transformed from something ambiguous (a "cool" reaction, after all, may lack warmth or interest) into something emphatically positive.
The commercialisation of modern youth culture has created a new uncertainty surrounding cool. To adults unschooled in the byways of yoof, being "cool" can appear to be simply about wearing the right trainers or having the latest iPod. But as any wise teenager will tell you, the truly cool people are those who don't try too hard—who are just innately cool. Coolness, in other words, defies definition; it is in some sense beyond language. And that is why the word itself is oddly appropriate: when people describe something as "cool," they are in effect acknowledging the limits of language—or at any rate of their own inability to say something more imaginative.
