This book is a collection of the best parts of the two works "Human Nature's Weaknesses" and "Human Nature's Strengths", named "Human Nature", with a more distinctive theme, which can make it easier for readers to absorb the essence of Carnegie's thoughts faster and better. Since the publication of Carnegie's work, it has changed the destiny of millions of people. Edison, the "king of inventions", Einstein, the originator of the theory of relativity, Mahatma Gandhi of India, Reeves and his sons, the creators of miracles in the construction industry, Hilton, the hotel industry tycoon, Ray Kroc, the founder of McDonald's, etc., Were all deeply influenced by Carnegie's thoughts and views. Carnegie's thoughts are extremely practical and instructive, as well as adaptable to all types of people in society and in all eras. As time goes by, Carnegie's thoughts and insights have not been abandoned by the times; on the contrary, in today's fiercely competitive society, his thoughts and insights are more profound and practical, and have more guiding significance for people. Reading this book will change your destiny and let you have a beautiful, happy and successful life.