You cannot solve current problems with current thinking. Current problems are the result of current thinking.
The most practical solution is a good theory.
A man should look for what is, and not for what he thinks should be.
Everything has changed except the way man thinks (when the hydrogen bomb was exploded)
Creativity is the residue of time wasted.
Gradually the conviction gained recognition that all knowledge about things is exclusively a working-over of the raw material furnished by the senses. ... Galileo and Hume first upheld this principle with full clarity and decisiveness.