LAERTES        The chariest maid is prodigal enough

If she unmask her beauty to the moon.

Virtue itself scapes not calumnious strokes.

The canker galls the infants of the spring

Too oft before their buttons be disclosed,

And in the morn and liquid dew of youth

Contagious blastments are most imminent.

Be wary then: best safety lies in fear,

Youth to itself rebels, though none else near.         (1.3.35-43)

After a small outburst of apparently genuine apprehension, Laertes retreats to his commonplace book, ‘chastity’ perhaps, or ‘maidenhood’, or ‘shamefastness’, with some relief, heading towards a nice rhyming couplet. The chariest maid is prodigal enough if she unmask her beauty to the moon: you can show your face properly, look directly and openly at the moon, goddess of chastity, by yourself, at night! That’s quite enough in the way of exposure! Otherwise, keep yourself to yourself, don’t look anyone in the eye, keep your mask on (sometimes worn outdoors by well-to-do women), or a veil. Don’t put yourself forward; make yourself disappear! Because virtue itself scapes not calumnious strokes: even the most virtuous woman can become the subject of gossip, innuendo, insult—in fact she’s more vulnerable to it! A young woman’s reputation is so fragile! The canker galls the infants of the spring too oft before their buttons be disclosed: it’s the tenderest shoots of plants which are most vulnerable to disease and pests (caterpillars, phallic, OBVIOUSLY), even before they’re in bud, before they’ve even hinted at their flowers, and in the morn and liquid dew of youth contagious blastments are most imminent. It’s in the most perfect dawn, when the dew is lying pure on the grass, that violent winds, polluted breezes, are at their most destructive. Youth, it’s a dangerous, dangerous time! Everything that seems lovely is perilous! Be wary then, Laertes concludes. Best safety lies in fear. Being afraid will keep you safe. Youth to itself rebels, thou none else is near: because it’s the natural condition of being young to take risks and to do stupid, foolish things even without being tempted to do so.

Poor Laertes, for all his self-righteousness and pomposity, he’s worked himself up into a state of real paranoia; perhaps, though, he can realise that he’s being ridiculously sententious, that his sister is, in fact, no fool—he just feels he has to go through the motions, and then can’t stop himself, the commonplaces just keep coming. And it’s a cover for what he also wants to say: I’ll miss you, I’m a bit worried about you, look after yourself, OK? (Poor Ophelia more, though.)