These are the 5 books Bill Gates recommends you read this summer

In this book, the longest of Gates' suggestions, acclaimed biographer Walter Isaacson takes on Leonardo da Vinci, who Gates describes as "one of the most fascinating people ever."

More than a painter, Leonardo was an inventor, engineer, medical researcher and more.

"When you look across all of Leonardo's many abilities and his few failings, the attribute that stands out above all else was his sense of wonder and curiosity," Gates writes.

"When he wanted to understand something — whether it was the flow of blood through the heart or the shape of a woodpecker's tongue — he would observe it closely, scribble down his thoughts, and then try to figure it all out," he wrote.

According to Gates, Isaacson does a great job pulling all the different aspects of Leonardo's life together, no easy task.

"More than any other Leonardo book I've read, this one helps you see him as a complete human being and understand just how special he was. He came close to understanding almost all of what was known on the planet at the time."

Historian David Christian is the creator of Big History, a free online course that traces what we know about the past 13.7 billion years of existence, going from the Big Bang and the origin of life to the complex societies we live in today.

The project is something Gates describes as his "favorite course of all time," so it's no surprise that he loves this book, which relates much of that history.

The book "will leave you with a greater appreciation of humanity's place in the universe," Gates glows.

"It shows how everything is connected to everything else, weaving together insights and evidence from across disciplines into a single, understandable narrative," he writes.

If you haven't taken the course, Gates says this book is an excellent way to understand its concepts. And if you have taken it, Gates calls the book a great refresher and an update, with some new material.

"I thought I knew everything I needed to know about Abraham Lincoln, but this novel made me rethink parts of his life," Gates writes of a book he calls an "all-American ghost story."

"Lincoln in the Bardo" is a novel that blends fiction with history and takes place in one night shortly after the death of Lincoln's 11-year-old son Willie. The "bardo" itself is a purgatory-like state where spirits linger, drawn from Tibetan Buddhist tradition.

After Lincoln visits his son's grave, Willie's spirit refuses to depart, despite the pleading from other spirits in the bardo.

In the story, Lincoln's contemplation of the loss of his son — one year after the start of the Civil War — gives him a new understanding of the grief experienced by families losing children in battle.

As Gates writes, we don't know that Willie's death changed the way Lincoln approached the war. But we can imagine that Lincoln's grief bolstered his resolve to ensure the war's outcome justified its heavy losses.

It's a book Gates says he found mysterious and surprisingly funny, and one that he couldn't wait to discuss with friends.

Global-health lecturer Hans Rosling died last year. In this book, a parting message that Rosling described as his "last battle in my life-long mission to fight devastating ignorance," you can see many of the same messages that Gates spends much of his time trying to get people to understand.

Life is getting much better, though the world still can be improved.

The late lecturer and his son and daughter-in-law analyze what they say are the ten instincts that distort our perspective on the world, leading us to dramatically underestimate the amount of progress we've made as a society.

When we get too distracted by thinking things are worse than they are, we lose the ability to focus on issues of real concern, the authors argue.

"It's a fitting final word from a brilliant man, and one of the best books I've ever read," Gates writes.