I've often said that my rats have taught me much more than I've taught them.

I may say that the only differences I expect to see revealed between the behavior of the rat and man (aside from enormous differences of complexity) lie in the field of verbal behavior.

The problem of far greater importance remains to be solved. Rather than build a world in which we shall all live well, we must stop building one in which it will be impossible to live at all.

The mob rushes in where individuals fear to tread.

But restraint is the only one sort of control, and absence of restraint isn't freedom. It's not control that's lacking when one feels 'free', but the objectionable control of force.

Let men be happy, informed, skillful, well behaved, and productive.

If you're old, don't try to change yourself, change your environment.