The human nature always prevails

LEONATO:

For there was never yet philosopher
That could endure the toothache patiently,
However they have writ the style of gods
And made a push at chance and sufferance.

William Shakespeare - Much ado about nothing (5.1)

There are no real men left

BEATRICE: But manhood is melted into curtsies, valour into compliment, and men are only turned into tongue, and trim ones too. He is now as valiant as Hercules that only tells a lie and swears it.

William Shakespeare - Much ado about nothing

Don't mix friendship with love

CLAUDIO:

Friendship is constant in all other things
Save in the office and affairs of love.
Therefore all hearts in love use their own tongues,
Let every eye negotiate for itself
And trust no agent, for beauty is a witch
Against whose charms faith melteth into blood.

William Shakespeare - Much ado about nothing

Beatrice compares marriage to a dance

BEATRICE: For hear me, Hero: wooing, wedding and repenting is as a Scotch jig, a measure and a cinque-pace: the first suit is hot and hasty like a Scotch jig, and full as fantastical, the wedding mannerly-modest as a measure, full of state and ancientry, and then comes repentance and, with his bag legs, falls into the cinque-pace faster and faster, till he sinks into his grave.

William Shakespeare - Much ado about nothing

The bachelors' credo

BENEDICK: Because I will not do them the wrong to mistrust any, I will do myself the right to trust none. And the fine is - for the which I may go the finer - I will live a bachelor.

William Shakespeare - Much ado about nothing

Men's 'love oaths' are not to be trusted

BEATRICE: [...] I had rather hear my dog bark at a crow than a man swear he loves me.

William Shakespeare - Much ado about nothing (I.1)