The greatest weapons in the conquest of knowledge are an understanding mind and the inexorable curiosity that drives it on.

Flattery is useful when dealing with youngsters.

It is always useful, you see, to subject the past life of reform politicians to rather inquisitive research.

I don't believe in personal immortality; the only way I expect to have some version of such a thing is through my books.

What do you call that nice, shiny white metal they use to make sidings and airplanes out of? Aluminum, right? Aluminum, pronounced 'uh-LOO-mih-num', right? Anybody knows that! But do you know how the British spell it? 'Aluminium', pronounced 'Al-yoo-MIH-nee-um'. Ever hear anything so ridiculous? The French and Germans spell it 'aluminium', too, but they're foreigners who don't speak Earth-standard. You'd think the British, however, using our language, would be more careful

The final end of Eternity, and the beginning of Infinity

The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom.