Mankind, Immanuel Kant

Out of the crooked timber of humanity, no straight thing was ever made.

- Immanuel Kant, in Idea for a General History with a Cosmopolitan Purpose (1784), Proposition 6.

http://en.wikiquote.org/wiki/Mankind

Attitude, Timothy Bentley

Whenever you're in conflict with someone, there is one factor that can make the difference between damaging your relationship and deepening it. That factor is attitude.

~ Timothy Bentley ~

Work, Mortimer Adler

Work that is pure toil, done solely for the sake of the money it earns, is also sheer drudgery because it is stultifying rather than self improving.

- Mortimer Adler, A Vision of the Future : Twelve Ideas for a Better Life and a Better Society (1984).

http://en.wikiquote.org/wiki/Work

Endeavor, Turkish Proverb

Measure a thousand times and cut once.

- Turkish Proverb

천번 재고, 단번에 베라.

- 터키속담