'Why We Sleep' by Matthew Walker explores the vital importance of sleep, how it affects our health, and the consequences of sleep deprivation. The book delves into the science behind sleep, offering insights into why we need it and how it influences our cognitive functions, physical health, and overall well-being.

Matthew Walker is a professor of neuroscience and psychology at the University of California, Berkeley. He is a renowned sleep expert who has conducted extensive research on the impact of sleep on human health. Walker is the author of the book 'Why We Sleep,' which aims to educate the public on the importance of sleep.

'Why We Sleep' covers a range of topics related to sleep, including the stages of sleep, the impact of sleep on learning and memory, the health consequences of sleep deprivation, and the role of dreams. The book also offers practical advice on how to improve sleep quality and discusses the societal implications of widespread sleep neglect.

According to 'Why We Sleep,' sleep is crucial for maintaining cognitive functions, physical health, and emotional stability. It plays a vital role in memory consolidation, immune system functioning, and metabolic regulation. Lack of sleep can lead to a range of health issues, including increased risk of chronic diseases, impaired cognitive performance, and mood disorders.

'Sapiens: A Brief History of Humankind' by Yuval Noah Harari takes a big-picture view of human history. It explains the main themes of human evolution and development without getting bogged down in details. The book also debunks many popular myths about human history, such as the idea that people today live happier lives or have better diets than our hunter-gatherer predecessors. It ends with an epilogue discussing the future of humankind in light of accelerating technological progress, making it particularly relevant given recent advances in AI.

'Sapiens: A Brief History of Humankind' discusses several main themes, including the cognitive revolution, the agricultural revolution, the unification of humankind, and the scientific revolution. The book explores how these events have shaped human societies, cultures, and economies. It also delves into the impact of technological advancements on the future of humanity.

Yuval Noah Harari is an Israeli historian and professor in the Department of History at the Hebrew University of Jerusalem. He is known for his bestselling books 'Sapiens: A Brief History of Humankind', 'Homo Deus: A Brief History of Tomorrow', and '21 Lessons for the 21st Century'. Harari's work focuses on broad historical processes and their implications for the future.

Pros of 'Sapiens: A Brief History of Humankind' include its broad, comprehensive view of human history and its ability to debunk popular myths. The book is also praised for its engaging writing style and thought-provoking insights. Cons might include its broad scope, which can sometimes lead to oversimplification of complex historical events, and the fact that some readers may find its speculative future predictions less convincing.