All the energy you put into things you can't control comes at the expense of things you can control.

Nothing is settled; no truth finds general acceptance. What we do one year we undo the next, and do over again the year following. Our energy is wasted in, and our prosperity suffers from, experiments endlessly repeated.

you cannot maximize two things that are both dependent on the same resource: time.

The threat to our way of life is a consequence of our way of life. That's what unsustainability means.

We cannot all do everything.

There is nothing exempt from the peril of mutation.

Nothing can stay the same forever, in business or in life, and counting on the status quo can only lead to grief.

Remember that there is nothing stable in human affairs, therefore avoid undue elation in prosperity or undue depression in adversity.

On n'est jamais content là où l'on est.

All of our boasted wealth, wonderful inventions and incalculable mechanical power will prove to be an unstable foundation if we continue to dwell together in strife—individual against individual, class against class, nation against nation.

In a world of scarce resources, globalization without new technology is unsustainable.

All human endeavor is killing time. All of it.

Every choice is made in the uncaring blind, no guarantees from the world around us.

In any race between human numbers and natural resources, time is against us.