The images evoked by words being independent of their sense, they vary from age to age and from people to people, the formulas remaining identical. Certain transitory images are attached to certain words: the word is merely as it were the button of an electric bell that calls them up.
All words and all formulas do not possess the power of evoking images, while there are some which have once had this power, but lose it in the course of use, and cease to waken any response in the mind. They then become vain sounds, whose principal utility is to relieve the person who employs them of the obligation of thinking. Armed with a small stock of formulas and commonplaces learnt while we are young, we possess all that is needed to traverse life without the tiring necessity of having to refiect on anything whatever.