Once you have made a careful decision based on facts, go into action. Don't stop to reconsider. Don't begin to hesitate, worry, and retrace your steps. Don't lose yourself in self-doubting which begets other doubts. Don't keep looking back over your shoulder.
Dale CarnegieLet's find and remedy all our weaknesses before our enemies get a chance to say a word. That is what Charles Darwin did. ...When Darwin completed the manuscript of his immortal book "The Origin Of Species" he realized that the publication of his revolutionary concept of creation would rock the intellectual and religious worlds. So he became his own critic and spent another 15 years checking his data, challenging his reasoning, and criticizing his conclusions.
Dale CarnegieMillions of people have wrecked their lives in angry turmoil, because they refused to accept the worst; refused to try to improve upon it; refused to salvage what they could from the wreck. Instead of trying to reconstruct their fortunes, they engaged in a bitter and "violent contest with experience"- and ended up victims of that brooding fixation known as melancholia.
Dale Carnegie