Piecemeal social engineering resembles physical engineering in regarding the ends as beyond the province of technology.

Propose theories which can be criticized. Think about possible decisive falsifying experiments-crucial experiments. But do not give up your theories too easily-not, at any rate, before you have critically examined your criticism.

If we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.

The conspiracy theory of society... comes from abandoning god and then asking: "Who is in his place"

We do not know. We can only guess.

Genuine philosophical problems are always rooted outside philosophy and they die if these roots decay.

Good tests kill flawed theories; we remain alive to guess again.