he who sees several enterprises turn out contrary to his wishes becomes dissatisfied with both men and things, and on the slightest provocation flies into a rage with people, with undertakings, with places, with fortune, or with himself. In order, therefore, that the mind may be at peace, it ought not to be hurried hither and thither, nor, as I said before, wearied by labour at great matters, or matters whose attainment is beyond its strength. It is easy to fit one’s shoulder to a light burden, and to shift it from one side to the other without dropping it: but we have difficulty in bearing the burdens which others’ hands lay upon us, and when overweighted by them we fling them off upon our neighbours. Even when we do stand upright under our load, we nevertheless reel beneath a weight which is beyond our strength.
simple and manageable undertakings proceed according to the pleasure of the person in charge of them, but enormous ones, beyond his capacity to manage, are not easily undertaken. When he has got them to administer, they hinder him, and press hard upon him, and just as he thinks that success is within his grasp, they collapse, and carry him with them: thus it comes about that a man’s wishes are often disappointed if he does not apply himself to easy tasks, yet wishes that the tasks which he undertakes may be easy. Whenever you would attempt anything, first form an estimate both of your own powers, of the extent of the matter which you are undertaking, and of the means by which you are to accomplish it: for if you have to abandon your work when it is half done, the disappointment will sour your temper. In such cases, it makes a difference whether one is of an ardent or of a cold and unenterprising temperament: for failure will rouse a generous spirit to anger, and will move a sluggish and dull one to sorrow. Let our undertakings, therefore, be neither petty nor yet presumptuous and reckless: let our hopes not range far from home: let us attempt nothing which if we succeed will make us astonished at our success.
Since we know not how to endure an injury, let us take care not to receive one: we should live with the quietest and easiest-tempered persons, not with anxious or with sullen ones: for our own habits are copied from those with whom we associate, and just as some bodily diseases are communicated by touch, so also the mind transfers its vices to its neighbours.