LAERTES
Fear it, Ophelia; fear it, my dear sister,
And keep you in the rear of your affection,
Out of the shot and danger of desire.
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.
(1.3.37-48)
Laertes insists that Ophelia should fear premarital sex because a "deflowered" woman is seen as damaged goods that no man will want to marry. This speech is also full of vivid innuendo, as when he compares intercourse to a "canker" worm invading and injuring a delicate flower before its buds, or "buttons," have had time to open (1.3.39-40). Nice. It's not quite as creepy as Hamlet's fixation with his mom, but it's pretty close.
Quote 5
LAERTES
[…] Then, if he says he loves
you,
It fits your wisdom so far to believe it
As he in his particular act and place
May give his saying deed, which is no further
Than the main voice of Denmark goes withal.
Then weigh what loss your honor may sustain
If with too credent ear you list his songs
Or lose your heart, or your chaste treasure open
To his unmaster'd importunity.
Fear it, Ophelia; fear it, my dear sister,
And keep you in the rear of your affection,
Out of the shot and danger of desire.
(1.3.27-39)
Laertes tells her to guard her "chaste treasure" —not because he's interested in chastity as a moral issue (this isn't about Promise Keepers), but because he believes Ophelia's virginity is literally valuable. It'll determine what kind of marriage offers she'll get, and what kind of family she—and he—can align themselves with.
History Snack: In Shakespeare's day, there were plenty of handbooks on this matter, including Juan Vives's Education of a Christian Woman, which says a maid "hath within her a treasure without comparison." (Vives's handbook was translated from Latin and published in English in 1592.) Another handbook called A Godly Form of Household Government (1603) says that a woman's virginity is "the best portion, the greatest inheritance, and the most precious jewel" of her dowry. Why all this talk of treasure? Well, in the 16th and 17th centuries, eldest sons inherited all their fathers' wealth, titles, and lands (this is called "Primogeniture"). Marrying a virgin insured (theoretically) that a man's children were legitimate and that the family wealth could be passed on from generation to generation. So, literally, marrying a virgin was like insuring your fortune: just good business.
Quote 6
LAERTES
Too much of water hast thou, poor Ophelia,
And therefore I forbid my tears. But yet
It is our trick; nature her custom holds,
Let shame say what it will. When these are gone,
The woman will be out.—Adieu, my lord.
I have a speech of fire, that fain would blaze,
But that this folly drowns it.
(4.7.211-217)
When Laertes learns that Ophelia has drowned, he associates his watery tears with the "too much water" Ophelia has inside her. But grief doesn't appear to be very manly —he says that as soon as his tears dry up "the woman will be out" of him. Does that mean Hamlet has been acting like a woman this whole play? And is that maybe one reason he seems to have such a bee in his bonnet about them?