Human beings are not very good at taking losses or admitting failure.

Failure cannot cope with persistence.

[T]o remain in a continually exalted moral condition is not human nature.

It is not in the nature of any people that it should willingly endure being ruled by another people, whether it is ruled ill or ruled well.

I don't give you permission to fail.

A man without persistence will never make a good shaman or a good physician.

Failure is man-made circumstance. It is never real until accepted by man as permanent.

No man leaves where he is and seeks a distant place unless he is in some respect a failure.

human nature (Jewish included) cannot remain tied down to all eternity.

A man without regrets cannot be cured.

If failure is not an option, then neither is success.

The human spirit will not invest itself in a compromise.

Man is certain of nothing but his ability to fail

It is impossible to succeed without failing.