The quality or state of being hard, literally or figuratively.
The cohesion of the particles on the surface of a body, determined by its capacity to scratch another, or be itself scratched;-measured among minerals on a scale of which diamond and talc form the extremes.
The peculiar quality exhibited by water which has mineral salts dissolved in it. Such water forms an insoluble compound with soap, and is hence unfit for washing purposes.
The work of art, just like any fragment of human life considered in its deepest meaning, seems to me devoid of value if it does not offer the hardness, the rigidity, the regularity, the luster on every interior and exterior facet, of the crystal. Pope Paul VI
I think there is only one quality worse than hardness of heart and that is softness of head. Theodore Roosevelt
I find myself so easily discouraged. It is pathetic how easily I can be discouraged - easily discouraged by resistance, easily discouraged by opposition, easily discouraged by hardness of heart, easily discouraged by blindness. C. J. Mahaney
Jazz vision is the fusion of music and art a real paradox of same-yet different. Here we play in exchanges, like the hardness of the key of c# major and from the softness of Db major - capturing, reflecting and improvising. Barbara Januszkiewicz
Every man of action has a strong dose of egoism, pride, hardness, and cunning. But all those things will be regarded as high qualities if he can make them the means to achieve great ends. Giorgos Seferis