To be able to advance much in perfection it is necessary to apply ourselves to one thing by itself - to a single book of devotion , to a single spiritual exercise, to a single aspiration, to a single virtue, and so on. Not, indeed, that all other things ought to be quite rejected and passed by, but in such a way that this to whichone is applying himself may usually be aimed at more in particular and as the special object of the most frequent effort, so that if one chance to turn to others, these may be like accessories. To do otherwise, by passing from one exercise to another, is to imitate those who spoil their appetite at a banquet by tasting a little of every delicacy. It is perpetually seeking, and never attaining, the science of the Saints, and so it results in losing that tranquillity of spirit in God, which is the "one thing needful" that Mary chose. We must, however, guard ourselves here from one fault, into which many fall. It is that of attaching ourselves too much to our own practices and spiritual exercises. This, naturally, makes us feel dislike for all methods not conformed to our own; for each one thinks that he employs the only suitable one, and cinsiders as imperfect those who do not work in the same way. Whoever has a good spirit draws edification from everything, and condemns nothing.