Reason and love keep little company together now-a-days.

William Shakespeare Wikipedia: William Shakespeare  

A Midsummer Night’s Dream, act 3, scene 1, Bottom

My love is as a fever, longing still
For that which longer nurseth the disease;
Feeding on that which doth preserve the ill,
The uncertain sickly appetite to please.
My reason, the physician to my love,
Angry that his prescriptions are not kept,
Hath left me, and I desperate now approve,
Desire his death, which physic did expect.
Past cure I am, now reason is past care,
And frantic-mad with evermore unrest;
My thoughts and my discourse as madmen’s are,
At random from the truth vainly express’d;

For I have sworn thee fair, and thought thee bright,
Who art as black as hell, as dark as night.

William Shakespeare Wikipedia: William Shakespeare  

Sonnet 147

Love is a familiar. Love is a devil. There is no evil angel but Love.

William Shakespeare Wikipedia: William Shakespeare  

Love’s Labour’s Lost, act 1, scene 2, Don Adriano de Armado

Few love to hear the sins they love to act.

If music be the food of love; play on.

When valour preys on reason, it eats the sword it fights with.

William Shakespeare Wikipedia: William Shakespeare  

Antony and Cleopatra, act 3, scene 13, Domitius Enobarbus

They do not love that do not show their love.

William Shakespeare Wikipedia: William Shakespeare  

Two Gentlemen of Verona, act 1, scene 2, Julia

How can that be true love which is falsely attempted?

William Shakespeare Wikipedia: William Shakespeare  

Love’s Labour’s Lost, act 1, scene 2, Don Adriano de Armado

Who can sever love from charity?

William Shakespeare Wikipedia: William Shakespeare  

Love’s Labour’s Lost, act 4, scene 3, Biron

When love speaks, the voice of all the gods makes heaven drowsy with the harmony.

William Shakespeare Wikipedia: William Shakespeare  

Love’s Labour’s Lost, act 4, scene 3, Biron