Mutability of temper and inconsistency with ourselves is the greatest weakness of human nature.

Amiable weaknesses of human nature.

The commonest weakness of our race is our ability to rationalize our most selfish purposes.

Weaknesses in men of genius are usually an exaggeration of their personal feeling; in the hands of feeble imitators they become the most flagrant blunders. Entire schools have been founded on misinterpretations of certain aspects of the masters. Lamentable mistakes have resulted from the thoughtless enthusiasm with which men have sought inspiration from the worst qualities of remarkable artists because they are unable to reproduce the sublime elements in their work.

Madam, the commonest weakness of our race is our ability to rationalize our most selfish purposes.

The intellect is the most incredible human capacity. It is the highest of all human capacities, actually. However, it is also the thing that can go most terribly wrong, because the intellect can become arrogant about its own existence and its accomplishments, and it can fall in love with its own products. That's what happens with ideologies. You become obsessed with a human-constructed dogma of which you believe is 100% right, and it eradicates the necessity of anything transcendent.

The point is that humans are rarely at their best when they use rational reasoning.

General ideas are no proof of the strength, but rather of the insufficiency of the human intellect.

There is one weakness in people for which there is no remedy. It is the universal weakness of LACK OF AMBITION!

It is a common failing of mortals to deem the more difficult the fairer.

I sometimes think that my own weakness lies in not realizing the full depths of the weakness and stupidity of men. As a reasonable creature myself I seem to have an unfortunate tendency to expect others unlike myself to be reasonable.

Upon reflection, I decided I had three main weaknesses: I was confused (evidenced by a lack of facts, an inability to coordinate my thoughts, and an inability to verbalize my ideas); I had a lack of confidence, which cause me to back down from forcefully stated positions; and I was overly emotional at the expense of careful, 'scientific' though. I was thirty-seven years old and still discovering who I was.

"One of the main weaknesses of mankind is the average man's familiarity with the word "impossible." He knows all the rules which will NOT work. He knows all the things which CANNOT be done."

For vice has this defect; it cannot be truly intelligent. Its very motives are its weakness.