"When you know a thing, to hold that you know it; and when you do not know a thing, to allow that you do not know it; this is knowledge."
- Confucius, Analects
"There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common."
- Denis Diderot
"To be conscious that you are ignorant is a great step to knowledge."
- Disraeli, Sybil
"One cannot know everything."
- Horace
"Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it."
- Samuel Johnson, Boswell's Life of Johnson
