This book is a real-life account of a young Jewish girl hiding from the Nazis during World War II, written in diary format. The girl and her family are forced to live in a secret annex in Amsterdam for two years, during which she writes about her experiences, fears, dreams, and the onset of adolescence. The diary provides a poignant and deeply personal insight into the horrors of the Holocaust, making it a powerful testament to the human spirit.

"Ethics" is a philosophical work that explores complex ideas about God, the universe, human emotions, and the path to enlightenment. The book outlines a metaphysical, epistemological, and ethical system in which God and the universe are one and the same, rejecting traditional notions of a personal deity and asserting that understanding the natural world leads to peace of mind and happiness. The work delves into the nature of the human mind and its emotions, advocating for the pursuit of reason and knowledge to achieve a calm, enlightened state.