Whoever is careless with the truth in small matters cannot be trusted in important affairs.

In the midst of difficulty lies opportunity.

When you look at yourself from a universal standpoint, something inside always reminds or informs you that there are bigger and better things to worry about.

Smoke like a chimney, work like a horse, eat without thinking, go for a walk only in really pleasant company.

If I had my life to live over again, I would elect to be a trader of goods rather than a student of science. I think barter is a noble thing.

The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.

The future is of greater interest to me than the past, since that is where I intend to spend the rest of my life.