The Heart in the Works of Shakespeare

You don't have to be Shakespeare to know that the heart is a powerful cultural symbol. If you've ever had a change of heart; if you've ever had a heart-to-heart with someone and poured your heart out to them; if you've ever had to learn something by heart even though your heart wasn't in it; then you know that heart metaphors and symbolisms abound in our everyday language and in the ways we structure our world. But Shakespeare, being Shakespeare, went a step (or two) further: In Shakespeare's works we essentially find a literary compendium of the metaphorical usage of the word heart, which brings to mind a quote by philosopher Rene Guenon: "At the heart of symbolism is found the symbolism of the heart."

Here is a sampler of heart meanings and metaphors from the works of William Shakespeare:

Heart = temperament
"In faith, lady, you have a merry heart." (Much Ado About Nothing, 2.1.280)
The lady of this quote seems to be of a truly happy and cheerful disposition.

Heart = feeling, way of expressing one's feelings
"If I could bid the fifth welcome with so good a heart..." (The Merchant of Venice, 1.2.122)
Here the phrase "with so good a heart" means "heartily".

Heart = high spirits, robust mental disposition
"I shall be out of heart shortly." (Henry IV, Part 1, 3.3.7)
"To be out of heart" means to be in low spirits, to feel disheartened.

Heart = life
"Cannot take two from twenty, for his heart, and leave eighteen." (Cymbeline, 2.1.49)
The phrase "for his heart" means "to save his life", "even if his life depended on it".

Heart = life force, fertility; therefore, heartless = barren
"How sighs resound through heartless ground..." (The Passionate Pilgrim, 18.35)

Heart = noble generosity, magnanimity
"My hearty friends..." (Antony & Cleopatra, 4.2.48)
By "hearty friends", Mark Antony means magnanimous friends.

Heart-blood/heart's blood = essence
"... the heart-blood of beauty..." (Troilus & Cressida, 3.1.32)

Heart-dear/heart's dear = beloved
"My heart's dear Harry..." (Henry IV, Part 2, 2.3.13)
The heart is the seat of love and affection.

Hearted = fixed in the heart
"... my cause is hearted..." (Othello, 1.3.390)
The heart is the center of determination and intent.

Heart-strings = nerves that (were thought to) sustain the heart; the deepest recesses of the heart; the most vital part of the heart.
"...but yet so false that he grieves my very heart-strings..." (The Two Gentlemen of Verona, 4.2.62)
Also:
"... from heart-string I love..." (Henry V, 4.1.103)
The heart is the core of one's being; it is the seat of one's deepest and most sincere feelings.

But the most important attribute of all is a good heart:
"... but a good heart, Kate, is the sun and the moon; or, rather, the sun, and not the moon; for it shines bright and never changes, but keeps his course truly." (Henry V, 5.2.154)

Sources:
Shakespeare Online: http://www.shakespeare-online.com
Merriam-Webster Online: http://www.m-w.com