Being busy does not always mean real work. The object of all work is production or accomplishment and to either of these ends there must be forethought, system, planning, intelligence, and honest purpose, as well as perspiration. Seeming to do is not doing

Intelligence is based on how efficient a species became at doing the things they need to survive.

When your intelligence don't tell you something ain't right, your conscience gives you a tap you on the shoulder and says 'Hold on'. If it don't, you're a snake.

I know that I am intelligent, because I know that I know nothing.

Everything has its limit - iron ore cannot be educated into gold.

The more intelligent a person is, the more he discovers kindness in others. For nothing enriches the world more than kindness. It makes mysterious things clear, difficult things easy, and dull things cheerful.