Tears harden lust, though marble wear with raining. [ William Shakespeare ]

Circumstances form the character; but, like petrifying matters, they harden while they form. [ Landor ]

Wealth and want equally harden the human heart, as frost and fire are both alien to the human flesh. Famine and gluttony alike drive nature away from the heart of man. [ Theodore Parker ]

It would not be more unreasonable to transplant a favorite flower out of black earth into gold dust than it is for a person to let money-getting harden his heart into contempt, or into impatience, of the little attentions, the merriments and the caresses of domestic life. [ Mountford ]

We have no permanent habits until we are forty. Then they begin to harden, presently they petrify, then business begins. Since forty I have been regular about going to bed and getting up - and that is one of the main things. I have made it a rule to go to bed when there wasn't anybody left to sit up with; and I have made it a rule to get up when I had to. This has resulted in an unswerving regularity of irregularity. It has saved me sound, but it would injure another person. [ Mark Twain, Seventieth Birthday speech ]