It is a curious paradox that several of the greatest and most creative spirits in science, after achieving important discoveries by following their unfettered imaginations, were in their later years obsessed with reductionist philosophy and as a result became sterile. Hilbert was a prime example of this paradox. Einstein was another. Like Hilbert, Einstein did his great work up to the age of forty without any reductionist bias. His crowning achievement, the general relativistic theory of gravitation, grew out of a deep physical understanding of natural processes. Only at the very end of his ten-year struggle to understand gravitation did he reduce the outcome of his understanding to a finite set of field equations. But like Hilbert, as he grew older he concentrated his attention more and more on the formal properties of his equations, and he lost interest in the wider universe of ideas out of which the equations arose.

His last twenty years were spent in a fruitless search for a set of equations that would unify the whole of physics, without paying attention to the rapidly proliferating experimental discoveries that any unified theory would finally have to explain. I do not need to say more about this tragic and well-known story of Einstein's lonely attempt to reduce physics to a finite set of marks on paper. His attempt failed as dismally as Hilbert's attempt to do the same thing with mathematics. I shall instead discuss another aspect of Einstein's later life, an aspect that has received less attention than his quest for the unified field equations: his extraordinary hostility to the idea of black holes.

"Einstein was remarkable for his powers of concentration; he could work uninterruptedly for hours and even days on the same problem. Some of the topics that interested him remained on his mind for decades. For relaxation he turned to music and to sailing, but often his work would continue during these moments as well; he usually had a notebook in his pocket so that he could jot down any idea that came to him. Once, after the theory of relativity had been put forth, he confessed to his colleague Wolfgang Pauli, "For the rest of my life I want to reflect on what light is." It is perhaps not entirely an accident that a focus on light is also the first visual act of the newborn child."

Albert Einstein once said: “When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge.”6

I didn’t arrive at my understanding of the fundamental laws of the universe through my rational mind.” — A. Einstein

It’s not that I’m so smart,” said Einstein, who was a consummate introvert. “It’s that I stay with problems longer.

"Throughout his life, Albert Einstein would retain the intuition and the awe of a child. He never lost his sense of wonder at the magic of nature's phenomena-magnetic fields, gravity, inertia, acceleration, light beams-which grown-ups find so commonplace. He retained the ability to hold two thoughts in his mind simultaneously, to be puzzled when they conflicted, and to marvel when he could smell an underlying unity. "People like you and me never grow old," he wrote a friend later in life. "We never cease to stand like curious children before the great mystery into which we were born.

Thanks to his own thought experiments, his formal education, and his study of authors like Foppl, Einstein already had identified the set of issues that would occupy him for years to come: the relation between electricity and magnetism, the putative role of the ether, and conceptions of space and time, as formulated by a philosopher like Kant or a scientific thinker like Maxwell. Einstein later recalled:

What made the greatest impression upon the student, however, was less the technical construction of mechanics or the solution of complicated problems than the achievements of mechanics in areas which apparently had nothing to do with mechanics: the mechanical theory of light, which conceived of light as the wave-motion of a quasi-rigid elastic ether and above all the kinetic theory of gases.

If you minimize objectivity, you ignore not only a lesson from Darwin but also one from Einstein. Einstein said that his successful theories came from “curiosity, concentration, perseverance, and self-criticism.” And by self-criticism, he meant the testing and destruction of his own well-loved ideas.

"Berlin suggests that "in the case of seminal discoveries-say of imaginary numbers, or non-Euclidean geometry, or the quantum theory- it is precisely dissociation of categories indispensable to normal human experience, that seems to be required, namely a gift of conceiving of what cannot in principle be imagined nor expressed in ordinary language." Like Newton and Copernicus, Einstein sustained a vision of a unified, harmonious, physically caused world. This dissociation led both to Einstein's genius in the world of physics and his inspirational, but ultimately less successful, forays into issues of world order."

Einstein said, ‘Not everything that counts can be counted, and not everything that can be counted counts.

Albert Einstein, in a classic humble brag, once remarked: “I have no special talents. I am only passionately curious.” The first half of that statement was surely false, while the second half was undoubtedly true.

When Einstein had thought through a problem, he always found it necessary to formulate this subject in as many different ways as possible and to present it so that it would be comprehensible to people accustomed to different modes of thought and with different educational preparations.

"Why does this magnificent applied science which saves work and makes life easier bring us so little happiness? The simple answer runs: because we have not yet learned to make sensible use of it. In war it serves that we may poison and mutilate each other. In peace it has made our lives hurried and uncertain. Instead of freeing us in great measure from spiritually exhausting labor, it has made men into slaves of machinery, who for the most part complete their monotonous long day's work with disgust and must continually tremble for their poor rations. It is not enough that you should understand about applied science in order that your work may increase man's blessings. Concern for the man himself and his fate must always form the chief interest of all technical endeavours; [..] concern for the great unsolved problems of the organization of labor and the distribution of goods in order that the creations of our mind shall be a blessing and not a curse to mankind.
Never forget this in the midst of your diagrams and equations.

- From a speech to students at the California Institute of Technology, in "Einstein Sees Lack in Applying Science", The New York Times (16 February 1931)"

There was a young fellow from Trinity
Who took
But the number of digits
Gave him the fidgets;
He dropped Math and took up Divinity.