No government has the right to decide on the truth of scientific principles, nor to prescribe in any way the character of the questions investigated. Neither may a government determine the aesthetic value of artistic creations, nor limit the forms of literacy or artistic expression. Nor should it pronounce on the validity of economic, historic, religious, or philosophical doctrines. Instead it has a duty to its citizens to maintain the freedom, to let those citizens contribute to the further adventure and the development of the human race.

We've learned from experience that the truth will out.

Teach principles not formulas.

Don't pay attention to "authorities," think for yourself.

The test of all knowledge is experiment. Experiment is the sole judge of scientific truth.

To test whether you have learned an idea or a definition, rephrase what you just learned without using the new word.

Words can be meaningless. If they are used in such a way that no sharp conclusions can be drawn.