Ad consilium ne accesseris, antequam voceris

Speak when you are spoken to, and come when you are called for. Advice should not, generally speaking, be offered until it is required, for, proffered service stinks. But if we see one, in whose welfare we feel ourselves interested, about to engage in a connection, or business, by which he is likely to be injured, it becomes then the part of a friend to interfere, and admonish him of his danger, though his opinion should not have been asked, or even though caution has been used, to keep the circumstance from his knowledge. Still the task is far from being grateful. «Le mauvais metier», Guy Patin says, «que celui de censeur; on ne gagne à l'exercer que la haine de ceux qu'on reprend, et on ne corrige personne», it is a bad business that of a censor, he is sure to incur the hatred of those he reproves, without having the pleasure of finding them improved by his advice. Ne prendre conseil que de sa tete, that is, Take counsel only of your own thoughts, the French say, but this is in some degree contradicted by the following: Un fou avise bien un sage, even a fool may suggest what may deserve the attention of a wise man; we should therefore listen to advice, let it come from what quarter it will, for Al buen consejo no se halla precio, good advice is inestimable.