Security and certainty

Security is mostly superstition. It does not exist in nature. Avoiding danger is no safer in the long run than outright exposure. The fearful are caught as often as the bold.

~ Helen Keller

Common sense is instinct. Enough of it is genius.

~ George Bernard Shaw

As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.

~ Albert Einstein