Jack Dorsey, the CEO and cofounder of Twitter and Square, is stretched to the limit this year running two publicly traded companies.
As he's matured as a leader, Dorsey has focused on pushing himself, and his favorite books offer insight into his thought process.
From a Product Hunt Q&A last year and his personal Twitter account, we've collected the books he's said have influenced him most.
'Tao Te Ching' by Lao Tzu
In the Product Hunt Q&A, Dorsey said his most prized possession is a copy of "Tao Te Ching" a friend gave him.
This ancient Chinese text (pronounced "Dow Dé Jing") is attributed to Lao Tzu. It became the foundation for Taoism in the sixth century BC and was first translated into English in the late 19th century.
It is composed of 81 poems that reflect on the Tao, which is the force behind everything in the universe.
Among themes explored are self-mastery through humility.
'The Score Takes Care of Itself' by Bill Walsh with Steve Jamison and Craig Walsh
Dorsey regularly recommends "The Score Takes Care of Itself" to entrepreneurs around Silicon Valley.
It's a guide to leadership by the late Bill Walsh, one of the greatest coaches in the history of the National Football League. It was published posthumously in 2010.
When Walsh became head coach of the San Francisco 49ers in 1978, they were the laughing stock of the league; over the next 10 years, the 49ers became a dynasty with four Super Bowl titles.
What makes his career even more remarkable is that he had a knack for finding and growing leaders, and his staff included eight future head coaches.
In his book, he explains the importance of creating a culture of high performancethrough personal encouragement and praise for exceptional work.
'Between the World and Me' by Ta-Nehisi Coates
Ta-Nehisi Coates' writing on American civil liberties exploded into the mainstream last year when "Between the World and Me" became a No. 1 bestseller and National Book Award winner.
In this book, Coates explores what it means to be an African-American man at this time in history, written as part memoir and part journalistic report, all framed as a letter to his young son.
The book is striking for both its commentary on American life as well as its meditation on what it takes to grow from a boy into a man.
'The Four Agreements' by Don Miguel Ruiz
Mexican writer Don Miguel Ruiz calls "The Four Agreements" a guide to inner peace based on ancient Mexican native spiritual teachings.
It's sold over five million copies in the US since it was published in 1997.
The book derives its name from the following precepts:
1. Be Impeccable With Your Word
2. Don't Take Anything Personally
3. Don't Make Assumptions
4. Always Do Your Best
'The Old Man and the Sea' by Ernest Hemingway
Ernest Hemingway's 1953 novella is a simple, concise story of an old man spending the day catching a massive marlin only to have ti picked apart by sharks by the time he reaches shore.
It offers a meditation on what drives us and why, and how we deal with the transient nature of accomplishment and happiness.
'The Checklist Manifesto' by Atul Gawande
All Square employees get a copy of "The Checklist Manifesto" on their first day at work, and Dorsey once tweeted that he's brought stacks of them to give away at Twitter.
In this 2009 book, surgeon and writer Atul Gawande argues that there are mistakes of ignorance and mistakes of ineptitude, and the latter category is most prevalent in the modern world. He believes clearly written guides and checklists are required for completing complex tasks to the best of your ability.
Gawande came to this conclusion when he and his team developed a safe surgery checklist that became a huge success around the world.
'The Yoga Sutras of Patañjali' by Edwin F. Bryant
Yoga in the Western world is largely secular, but this Hindu book from the year 400 is a guide that not only teaches you how to perform yoga exercises but how to use those motions and breathing patterns to connect with God.