One general rule of duty is to keep boys from associating with vicious persons; otherwise they will pick up something of their vice. This has been urged by Pythagoras among a number of dark sayings. Since these also possess great value as aids to the attainment of virtue, I will proceed to quote them, adding their explanation. _Do not taste black-tails_[59]—keep no company with persons who are malignant and therefore ‘black’. _Do not [Sidenote: E] step over a beam_—justice must be scrupulously respected and not ‘overstepped’. _Do not sit on a quart-measure_—beware of idleness, and see to the providing of daily bread. _Do not clasp hands with every man_—we should form no sudden connexions. _Do not wear a tight ring_—one should carry out the practice of [Sidenote: *] life, and not fasten it to any chain. _Do not poke a fire with iron_—do not irritate a wrathful man (the right course being to let angry men go their own way). _Do not eat the heart_—do not injure [Sidenote: F] the mind with worry and brooding. _Abstain from beans_—avoid public life (office in former times being determined by voting with beans). _Do not put victuals in a chamber-vessel_—clever speech ought not to be put into a wicked mind, since speech, which is the food of thought, is polluted by the wickedness in a man. _Do not turn back on coming to the border_—when about to die, and with the end of life close in sight, behave calmly and without losing heart. To return to the topic with which we were dealing before this digression. While, as I observed, boys should be kept from every kind of vicious company, especially should they be kept [Sidenote: 13] from parasites. I venture to repeat here what I am continually urging upon fathers. There is no set of creatures so pernicious—none which so quickly and completely brings youth to headlong destruction—as parasites. They are utter ruin to both father and son, filling the old age of the one and the youth of the other with vexation. To gain their purpose they offer an irresistible bait in the shape of pleasure. In the case of rich men’s sons, the father preaches sobriety, the parasite drunkenness. The father urges temperance and economy, the parasite profligacy and extravagance. The father says: ‘Be industrious’; the parasite says: ‘Be idle; for life is only a moment altogether. [Sidenote: B] One ought to live, not merely exist. Why trouble about your father’s threats? He is an old driveller with one foot in the coffin, and we will promptly pick him up on our shoulders and carry him off to his grave.’ One person tempts him with a drab, or with the seduction of a married woman, plundering and stripping the father of all the provision for his old age. They are an abominable crew; their friendship is a sham; of candour they have no idea; they toady the rich and despise the poor. They are drawn to young men like puppets on a string; they [Sidenote: *] grin, when those who feed them laugh; they