Date: 1603

"Bow, stubborn knees; and heart with strings of steel, / Be soft as sinews of the new-born babe"

— Shakespeare, William (1564-1616)

Date: 1603

"And let me wring your heart; for so I shall / If it be made of penetrable stuff, / If damnèd custom have not brassed it so / That it is proof and bulwark against sense."

— Shakespeare, William (1564-1616)

Date: 1603

"And my imaginations are as foul / As Vulcan's stithy."

— Shakespeare, William (1564-1616)

Date: 1604, 1622

A thought may, "like a poisonous mineral," gnaw one's inwards

— Shakespeare, William (1564-1616)

Date: 1611

"His heart is as firm as a stone; yea, as hard as a piece of the nether millstone."

— Author Unknown

Date: 1611

"And I will give them one heart, and I will put a new spirit within you; and I will take the stony heart out of their flesh, and will give them an heart of flesh."

— Author Unknown

Date: 1611

"Yea, they made their hearts as an adamant stone, lest they should hear the law, and the words which the LORD of hosts hath sent in his spirit by the former prophets: therefore came a great wrath from the LORD of hosts."

— Author Unknown

Date: 1632

"Looke as it is with a Gold smith that melteth the metall that he is to make a vessell of, if after the melting thereof, there follow a cooling, it had beene as good it had never beene melted, it is as hard, haply harder, as unfit, haply unfitter, then it was before to make vessell of; but after ...

— Hooker, Richard (1554-1600)

Date: 1633

"Our two soules therefore, which are one, / Though I must goe, endure not yet / A breach, but an expansion, / Like gold to ayery thinnesse beate."

— Donne, John (1572-1631)

Date: 1641

"As Lots wife was turned into a Pillar of Salt, that her inconstancie might be fixt, and yet be melting still: So, thou, my Soule, if I had my wish, shouldst be turned into a Pillar of Thoughts; that thy volubility might be restrain'd, and yet be thinking still."

— Baker, Richard, Sir (c. 1568-1645)