A life in which he questioned the “It from Bit”:
I think of my lifetime in physics as divided into three periods. In the first period, extending from the beginning of my career until the early 1950’s, I was in the grip of the idea that Everything Is Particles. I was looking for ways to build all basic entities – neutrons, protons, mesons, and so on – out of the lightest, most fundamental particles, electrons, and photons.
I call my second period Everything Is Fields. From the time I fell in love with general relativity and gravitation in 1952 until late in my career, I pursued the vision of a world made of fields, one in which the apparent particles are really manifestations of electric and magnetic fields, gravitational fields, and space-time itself.
Now I am in the grip of a new vision, that Everything Is Information. The more I have pondered the mystery of the quantum and our strange ability to comprehend this world in which we live, the more I see possible fundamental roles for logic and information as the bedrock of physical theory. – J. A. Wheeler, K. Ford, Geons, Black Hole, & Quantum Foam: A Life in Physics New York W.W. Norton & Co, 1998, pp 63-64.
Wheeler coined the term “black hole”:
Over a long, productive scientific life, he was known for his drive to address big, overarching questions in physics, subjects which he liked to say merged with philosophical questions about the origin of matter, information and the universe. He was a young contemporary of Albert Einstein and Niels Bohr, was a driving force in the development of both the atomic and hydrogen bombs and, in later years, became the father of modern general relativity.
See also: What great physicists have said about immateriality and consciousness