I used to think that Sir Isaac Newton, the great physicist, was INTP, but I was recently convinced otherwise. In this post I will attempt to explain why, but making use of the Jungian Functions to do so, this post is to be considered an advanced lesson.

Argument 1: Newton used Introverted Feeling (Fi) rather than Extroverted Feeling (Fe):

• Introverted Feeling (Fi) deals with wonder and with the essence of things as opposed to aesthetic beauty and the common (Fe). Newton derided art as useless. And conversely, he was intensely interested in alchemy, writing some 10,000 pages of esoteric, non-scientific enquiry into the occult nature of matter and so on.

• In describing his stance towards his fellow men, Newton said: “I do not know how I may appear to the world,but to myself I seem to have been only like a boy, playing on the sea-shore, and diverting myself, in now and then finding a smoother pebble or prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”

The poet and artist William Blake (INFP) famously depicted Newton sitting naked and crouched on a rocky outcropping covered with algae, apparently at the bottom of the sea. His attention is focused upon diagrams he draws with a compass upon a scroll that appears to unravel from his mouth. Blade was much opposed to Newton, for, as he wrote: ""Art is the Tree of Life. Science is the Tree of Death." Blake felt that by ordering the apparent chaos into scientific laws, Newton would destroy the divine chaos that had created him and all else. Thus Blake thought of Newton as a devil amongst men.

Argument 2: Newton used Extroverted Thinking (Te) rather than Introverted Thinking (Ti):

• As you probably learned in school, Newton and Gottfried Leibnitz (INTP) developed the mathematical instrument of calculus simultaneously. But where Leibnitz was interested in precision and in isolating and proving the principles of calculus for the sake of the principle itself (Ti), Newton’s system of calculus was messy and oriented towards utility – the solving concrete problems at hand (Te) – rather than towards principle itself. One could almost say that once Newton was convinced that his principles were true, he wouldn’t bother proving it true to others. – A classic trait of INTJs who, according to the Swiss psychiatrist Carl Jung, deal in oracular tones and visions – in fact, in describing Newton’s oracular approach to mathematics, the Hungarian mathemematician George Polya said:

“As a young student, [Newton] began the study of geometry … he read the theorems, saw that they were true, and omitted the proofs. He wondered why anybody should take pains to prove things so evident.”

History has preferred the Ti approach of Gottfried Leibnitz over the Te approach of Isaac Newton as the latter’s was embedded in the solving of concrete problems rather than pure principle.

Argument 3: Newton used Introverted iNtuition (Ni) and displayed the ambition and narcissism that usually goes along with it:

• As we have noted elsewhere on this site, both INTJs and INFJs often display traits of the narcissistic personality. In Jungian terms, this is because their primary function, Introverted iNtuition (Ni), is a perceiving function that is simultaneously imaginative and directed inwards. In other words, what they perceive within themselves appears to them as both more important and more true than the opinions of others. Of exactly this phenomenon the Ni dominant philosopher Schopenhauer said:

What this apple is doing in our post about Newton is unkown. Getting back to the matter at hand, Newton fervently tried to fuse his scientific findings with alchemical and occult knowledge. Unfortunately, nothing worthwhile appears to have come of his attempts to unify science with religion. Then as now, one should not confuse apples with oranges.

“It is only a man’s own thoughts that he really and completely understands. To read the thoughts of others is like taking the remains of someone else’s meal, like putting on the discarded clothes of a stranger.”

• Reading up on Newton’s biography, it soon becomes evident that the man was secretive, non-sharing and tried to destroy his opponents. In other words, he had a great ambition (Ni) which he naturally sought to externalize (Te). One could almost be led to believe that Newton were an ENTJ if he weren’t so universally described as an introvert.

• Furthermore, Newton was frequently described as unpleasant and self-serving. Of Newton’s grandeur and narcissism, the great psychologist and scientist H.J. Eysenck wrote:

[There was] a dispute between Newton and Leibnitz concerning the invention of the calculus. The two protagonists did not engage in the debate personally, but used proxies, hangers-on who would use their vituperative talents to the utmost in the service of their masters. Newton in particular abused his powers as President of the Royal Society in a completely unethical manner. He nominated his friends and supporters to a theoretically neutral commission of the Royal Society to consider the dispute; he wrote the report himself, carefully keeping his own name out of it, and he personally persecuted Leibnitz beyond the grave, insisting that he had plagiarized Newton’s discovery – which was clearly untrue, as posterity has found. Neither scientist emerged with any credit from the Machiavellian controversy … [but] Newton behaved similarly towards Robert Hooke, John Locke, and many others.

• So besides vaulting ambition and displaying delusions of grandeur (well, perhaps not quite so delusional given his genius, but still), Newton also displayed the drive towards synthesis and unison that is characteristic of Ni. In fact, towards the end of his life, Newton attempted to unify all of his different productions (science, alchemy, and religion) into a single unified system even though, as we know from Kant, such a unison is impossible. And to top it all off, Newton would insist that there was nothing wrong with his grand-yet-impossible synthesis. Rather if it seemed wrong, it was merely because the mastery of his model was inaccessible to “lesser natures” – a classic defense of INTJs whose ideas meet criticism.

Thus, all in all we believe Newton to be an INTJ.