When you look at evil, evil also looks at your heart like a mirror. Human nature is complex, and there is neither pure goodness nor pure evil. In many cases, the two are mutually transformed or exist.

Those who fight the devil should be careful not to become the devil. When you stare at the abyss from a distance, the abyss also stares at you. This sentence comes from Nietzsche's The Other Side of Good and Evil.

The other side of good and evil was written in the summer of 1885 and completed in the winter of the following year. There are two purposes in writing this book, one is to explain what Zarathustra said, and the other is to prepare for writing his greatest and most important book, Strong Will. In this book, Nietzsche tries to define the two relative words "good" and "evil" to distinguish immorality from immorality. He noticed that people's efforts to make ancient moral standards consistent with the needs of modern people were contradictory, and he realized that people often made compromises between moral theory and social practice. His aim is to establish the relationship between morality and need, and to build an operable foundation for human behavior.

Nietzsche, formerly known as Michael Tanner, is a philosopher, opera critic and lifelong researcher at the Eucharist College of Cambridge University. Research field:19th century German philosophy, especially Hegel and Nietzsche; Wagner as a cultural phenomenon; Philosophy of art; Contemporary critical thoughts and cultural studies. He is the author of Schopenhauer (1999), Nietzsche (2000) and Wagner (2008).