Kant wrote an essay on the vital powers: I should prefer to write a dirge and threnody on them, because their continual employment in banging and hammering and general noise-making has been a daily torment to me all my life. There are people, I know, indeed very many of them, who smile at these things, because they are insensitive to noise; but these are the same people who are insensitive to argument, to ideas, to poetry and works of art, in short to intellectual impressions of every kind, the reason being the tough constitution and firm texture of their brain. On the other hand, I have discovered complaints about the torment noise causes thinking men in the biographies or other personal statements of almost all the great writers, e.g. in Kant's, in Goethe's, in Lichtenberg's, in Jean Paul's; indeed, if such a complaint is missing, it is merely because the context failed to provide an opportunity for it. I explain the matter as follows: as when a large diamond is broken to pieces its value is equal to only so many little diamonds, or when an army is reduced to small units it becomes ineffective, so when a great mind is interrupted, disturbed and distracted it is capable of no more than a commonplace mind, because its superiority consists in concentrating all its forces on one single point and object, in the same way as a concave mirror concentrates all its rays, and this is precisely what noisy interruption prevents it from doing. That is why eminent minds have always been so extremely averse to every kind of disturbance, interruption and distraction, and most of all to violent interruption by noise, while the rest are not especially troubled by it. The most sensible and intelligent of all European nations has even called the rule "Never interrupt" the Eleventh Commandment. Noise, however, is the most impertinent of all interruptions, since it interrupts, indeed disrupts, even our thoughts. Where there is nothing to interrupt, to be sure, it will cause no especial discomfiture.