“We must learn, and we will learn!” exclaimed David Hilbert in 1930, during his speech for being honored as an honorary citizen of his hometown. Perhaps his optimism was excessive; or perhaps he was simply inviting his younger colleagues in science to continue the quest for knowledge, just as he had done throughout his career.

This book refers to that quest — in the pursuit of mathematical knowledge, but also to the people behind it. The mathematics of the 20th century is a wonderful mosaic of new ideas and new applications of older ones, among which are ideas and theories that, while not aligning with human intuition, have found application in our daily lives in many cases.

But this book, more than anything else, is a tribute to the people to whom we owe this knowledge. And if the stereotype many have in mind about mathematicians is that of the solitary and eccentric scientist, here you will find a multitude of characters — some extroverted and playful, others ascetic, some tormented, and others simply persecuted by the terrifying events that marked the past century.

As Hilbert himself said, let us lift the veil and see how history, human nature, and mathematical genius intertwine, and how all of this has directly influenced the way we live, think, and perceive the universal language of nature today.