If you’re still looking for a Christmas gift for the science nerd in your life, consider Leonardo da Vinci by Walter Isaacson.

The outstanding biography — from the same author who brought us Steve Jobs and Einstein — dissects the life of the complicated Renaissance artist with exquisite detail. We come to see da Vinci as not only an inventor of musical instruments and early flying machines, but also an obsessive notebook keeper and vegetarian, who had trouble finishing many of the projects and paintings he started.

Yet what is most thrilling is getting to know da Vinci the scientist. Isaacson explains how loving science and applying the scientific method to observing the world was really what made da Vinci a great artist and, Isaacson argues, a genius.

Da Vinci was obsessed with observing and understanding phenomena in nature, from the proportions of the human body to how the muscles of the lips moved. He wanted to know about everything around him, in minute detail, Isaacson writes. He wondered about questions “most people over the age of ten no longer puzzle about” — for instance, how the tongue of a woodpecker works.

To learn about the world, da Vinci blended his own observations with experimentation. Never formally schooled, “he preferred to induce from experiments rather than deduce from theoretical principles,” Isaacson explains. He recorded his observations, looked for patterns among them, and then tested those patterns through additional observation and experimentation.

When he became fascinated with the idea that he could invent flying machines, three and a half centuries before the Wright brothers flew the first airplane, he observed various birds and filled notebooks on the function and speed at which their wings flapped. That’s why Isaacson calls da Vinci “an exemplar of this scientific method.” He goes on:

“Galileo, born 112 years after Leonardo, is usually credited with being the first to develop this kind of rigorous empirical approach and is often hailed as the father of modern science,” the historian Fritjof Capra wrote. “There can be no doubt that this honor would have been bestowed on Leonardo da Vinci had he published his scientific writings during his lifetime, or had his Notebooks been widely studied soon after his death.

Da Vinci’s emphasis on empirical observation also helped him improve his art. First, he was able to use what he learned from looking at nature to paint and draw. His studies of the body, animals, motion, shadow and light, perspective and proportion helped him better understand what he was seeing in front of him, and render it in art more accurately and finely than anyone else of his time.

He also used his observations of nature to make connections among phenomena. He noticed that a fetus in a womb looked like a seed in a shell, Isaacson writes. A recorder was like a larynx in the throat. Here’s Isaacson again:

What Leonardo probably began as four distinct elements ended up woven together in a way that illustrates a fundamental theme in his art and science: the interconnectedness of nature, the unity of its patterns, and the analogy between the workings of the human body and those of the earth.

Most importantly, his curiosity-driven explorations, and ability to connect art and science, helped him innovate in his work. They helped him think differently, Isaacson argues. Da Vinci made an astoundingly diverse array of discoveries, including conceptualizing the helicopter and solar power and advancing knowledge about everything from the reproductive organs to botany.

This genius is also what drew Isaacson to Albert Einstein and Steve Jobs as subjects: They’re all innovators who were inspired by and drew connections between art and science.

“Leonardo da Vinci is the ultimate example of the main theme of my previous biographies: how the ability to make connections across disciplines — arts and sciences, humanities and technology — is a key to innovation, imagination, and genius,” Isaacson writes. And this wonderful book is a reminder, in a time of increasingly narrow specialization and focus, that the methods of Renaissance men like da Vinci are as relevant as ever.