If we spend our time with regrets over yesterday, and worries over what might happen tomorrow, we have no today in which to live.

Thomas Sowell

Throughout the infinite, the forces are in a perfect balance, and hence the energy of a single thought may determine the motion of a universe.

Nikola Tesla

It is not external events themselves that cause us distress, but the way in which we think about them... It is our attitudes and reactions that give us trouble. We cannot choose our external circumstances, but we can always choose how we respond to them.

Epictetus

They alone live, who live for others.

Swami Vivekananda

In all things that you do, consider the end.

Solon

The world owes you nothing. It was here first.

Mark Twain