Habits are comfortable, but when they fossilise, the humanity is gradually drained out of them - Theodore Zeldin, Intimate History of Humanity, p356
Habit is habit, and not to be flung out of the window by any man, but coaxed downstairs a step at a time - Mark Twain
For what else is this collection but a disorder to which habit has accommodated itself to such an extent that it can appear as order - Walter Benjamin
First we shape our tools - thereafter they shape us - Marshall McLuhan
All human activity is behaviour. Through the centuries we have developed codes of conduct, these become laid down by the society, by the culture, in which we live, and by the so-called saints and religious teachers; this code or pattern, this norm of behaviour, becomes traditional and automatic, that is, mechanical - J. Krishnamurti