If you are looking for a book to give you some optimism, this may be a good choice. Although reasonably long, it is packed with good stories and a positive take on human civilization. While doing this, the author manages to take down a number of more negative takes on human instincts including the Stamford Prison Experiment and other social psychology landmarks inspired by the horrors of the Second World War.
He finishes with ten pieces of advice, and I will limit myself to three of them. Firstly, when in doubt, assume the best (or, as Monty Python sung, “Always look on the bright side of life”). Secondly, ask more questions. Thirdly, be realistic. The book is a tonic in troubled times, and certainly helped me see things from a different perspective.