“There are three things extremely hard: steel, a diamond, and to know one's self.”

“Steel can be tempered and hardened, and so can men. In this world of struggle, which was not designed for softies, a man must be harder than what hits him. Yes, he must be diamond-hard. Then he'll not be "fed up" with his little personal troubles.”

Herbert N. Casson (1869–1951) Canadian journalist and writer

“I know that isn't always easy and that there is self-harm in the world. Sometimes it's hard for people to rise above things.”

Andrew Biersack (1990) American singer-songwriter

“What do nations care about the cost of war, if by spending a few hundred millions in steel and gunpowder they can gain a thousand millions in diamonds and cocoa?”

W.E.B. Du Bois (1868–1963) American sociologist, historian, activist and writer

“Our sages have taught us to learn one thing; `As in the Self, so in the Universe.' It is not possible to scan the universe as it is to scan the self. Know the self and you know the universe.”

Mahatma Gandhi (1869–1948) pre-eminent leader of Indian nationalism during British-ruled India

“The hardness of a diamond is part of its usefulness, but its true value is in the light that shines through it.”

B.K.S. Iyengar (1918–2014) Indian yoga teacher and scholar

“Extreme pride or dejection indicates extreme ignorance of self.”
Maxima superbia vel abjectio est maxima sui ignorantia.

Baruch Spinoza book Ethics

“It seems, we living the American dream
But people highest up got the lowest self esteem.
The prettiest people do the ugliest things
For the road to riches and diamond rings.”

Kanye West (1977) American rapper, singer and songwriter

“No it is not easy to write. It is as hard as breaking rocks. Sparks and splinters fly like shattered steel.”

Clarice Lispector book The Hour of the Star

“We want this people to be hard, not soft, and you must steel yourselves for it in your youth!”

Adolf Hitler (1889–1945) Führer and Reich Chancellor of Germany, Leader of the Nazi Party