Sir Isaac Newton is one of our greatest scientists to ever live. He promoted the empirical method, where ideas had to be tested for validity, and wrote the Principia Mathematica, which established classical mechanics. What is less well-known is that he struggled with mental illness, thus fitting the description of the mad genius.
At an early age, Newton exhibited symptoms of bipolar disorder. Romantic writers considered it an essential element of creativity, with a perfectionist born out of depression and manic episodes leading to intense periods of productivity. Newton was a solitary child who spent most of his time alone with his inventions. He was prone to rage, and on one occasion threatened to burn down the house with his mother and father in it. When he went to Cambridge, he found it difficult to make friends and experienced episodes of mania and depression. He couldn’t take criticism of his work, and for that reason, he withdrew from the scientific community.
Newton didn’t enjoy fame and often requested that his papers be published anonymously. When he fell into depression, he hallucinated and had conversations with absent people. Over time he became obsessed with religion, and in the 1690’s he wrote a number of religious tracts dealing with the literal and symbolic interpretations of the Bible.
Another thing that fascinated Newton was alchemy, which he spent twenty-five years studying in secret. He wrote thousands of pages on the subject. Among his notes, there are signs that he developed illusions of grandeur like so many bipolar people do. He wrote that he was appointed by God to bring truth to the world. Perhaps not such a crazy notion. After all, Newton was a key figure in bringing us science as we know it. For many of us, the belief in science has come to replace the belief in God.
After Newton’s death, his hair was examined and found to contain mercury. It was most likely a result of his experiments with alchemy. Mercury poisoning is also a possible explanation for his eccentricity late in life.