Natural forces are measurable only in the form in which we know them, and the measure of their effect is energy.

Whoever, in the pursuit of science, seeks after immediate practical utility may rest assured that he seeks in vain.

Sensory perceptions are signs whose meaning it is the task of our understanding to learn.

Educate the children and it will not be necessary to punish the men.

-- Pythagoras

Fables should be taught as fables, myths as myths, and miracles as poetic fancies.

-- Hypatia

To teach superstitions as truth is a most terrible thing.

-- Hypatia

Blue dye is extracted from the indigo plant, yet it is bluer than indigo itself.

-- Xunzi

An investment in knowledge pays the best interest.

-- Benjamin Franklin

Ignorance leads to fear, fear leads to hate, and hate leads to violence. This is the equation.

-- Averroes