There are three competing theories behind why the German philosopher Friedrich Nietzsche went insane: the first, the most popular, is that he contracted Neurosyphilis; the second, based on a study of his medical records, suggests that he began to show signs of dementia; the third is simply that he mentally saw things or thought things that pushed him over the edge.

In 1889, apparently while watching a horse being beaten in public, Nietzsche ran over and put his arms around it before having a nervous breakdown. He was never the same after that. And given that all of this took place some hundred years ago, without any strong evidence that suggests the exact cause of what happened to him, we can only speculate.

The first two options are as they are. If he contracted a disease or an illness that suddenly manifested in his body, that’s that. But what if he didn’t? Is it possible for someone to lose their sense of sanity simply by creating a mental world that they can no longer comprehend and make sense of?

The psychotherapist Carl Jung thought so. He, himself, being no stranger to living in a rich inner world created by the mind — a world of such depth that he thought it possible that he, too, might go insane at some point in his life — speculated that the cause of Nietzsche’s insanity was that he went so deep into the mental world of thoughts and abstractions that he could no longer pull himself together living in the regular day-to-day world.

There were years in Jung’s life where he went similarly deep into the bottomless pit of his inner being to come up with some of his theories that he suggested that the only reason he didn’t go insane was that he had a wife and kids who securely anchored him to the real world in front of him, and the responsibility they endowed on him meant that he could never let himself get unanchored from this base, no matter how deep he went.

Nietzsche, famously, died in the care of his sister, and for the most part, lived his life alone. He might even have died a virgin. Outside of a teaching post he held at the University of Basel, he spent most of his adult life in the company of the abstract ideas he shared with the world. It’s safe to say that Nietzsche’s inner life of ideas was richer than his outer life of experiences.

Most of us likely don’t have to worry about how deep we go into the chambers of the mind. Most people living in regular society are by default practical. But there is still something this anecdote touches on that is relevant to how each of us experiences the world, and it’s something that plays a fairly large role in the quality of our day to day experiences.

All of us have an inner experience and an outer experience of consciousness. The inner experience is private, intimate, and using language and thoughts, it creates our concept of self so that we can use it to relate to the world. In this world, we come face to face with our outer experience. There are other people around that we relate to, there are responsibilities and jobs we have to attend to, and there is simply mere survival on the line which means staying out of harm’s way and guiding ourselves towards some form of flourishing.

These two experiences, of course, relate to one and other, and they feed each other, growing and evolving together. That said, most of us have a disposition that leans towards one side at the expense of the other. In an individual, it’s usually not a balance but an asymmetry.

The terms introvert and extravert that Jung popularized broadly fit this distinction in terms of personality. Not entirely, because these terms represent more of a social preference, where you predominantly gain energy either from being alone or from being around other people, and outer experience isn’t always concerned with other people in that way. But there is overlap, and there is likely a correlation. The inner spiritual world and the outer materialist world is also a distinction that loosely fits this. But those terms are fairly loaded, meaning different things to different people.

Either way, each of our lives develops in two directions: They become more complex as we look inward, and they become more complex as we relate to the physical reality around us. And though we all have our own disposition towards one side or another, we grow best when the complexities growing in each direction harmonize with each other.

If we go by Jung’s speculation, based on this distinction, Nietzsche likely grew so complex in his inner world that the outer world stopped making sense to him. He likely saw or thought something that he shouldn’t have, in a way that he shouldn’t have — the one thing that provided so much of a cognitive dissonance that he broke. If all you have lived is in the world of ideas and thoughts and abstractions, without other people around whom you can develop in relation to, without experiences that ground you in the flesh and bones reality of the body and the physical laws that govern its growth and decay, then eventually, what’s out there will stop making sense to you in a way that you can meaningfully relate to.

On the other hand, if all you have ever done is spent your time growing in the outer world, with people constantly around, with more and more worldly experiences to fill your senses with, sooner or later, you will begin to feel a kind of shallowness, one which you will either choose to ignore by powering through or have to face head-on. Either way, while that may not lead to insanity, it can lead to a different kind of misery, one that feels lost even though everything in the surrounding environment is seemingly perfect.

If life is indeed guided by evolution as all of our evidence suggests, where the force underlying our thoughts and our actions leans towards continuous growth, what it is reaching for is an ever-increasing level of harmonized complexity. We strive to become more, whether internally or externally, in a way that we can handle and in a way that we can use to create a more complete sense of meaning in our lives.

That said, in order to do this in a way that doesn’t burn us out or that doesn’t lead us into an unsustainable cycle, we have to accept that living a full life means that we have to look both inwardly and outwardly — that we have to balance inner complexity with outer complexity.

Today, we live in an age of abundance, where most people’s basic needs have been met. Sure, things could always be better on a global scale, but the majority of the people in the world no longer have to worry about hunting or being hunted. This means that the outer world has gotten much more complex relative to our evolutionary programming. It also means that our interactions with this world take up more energy than they perhaps did when we lived in a simpler world, with fewer things vying for our attention.

In this world, our external incentives have, in a loose sense, forced far more extraversion or materialism than is likely healthy for that balance between inner and outer complexity. While Nietzsche might have gone insane from locking himself in a room with only his own ideas and thinking patterns to entertain him, many people today are falling into the opposite trap, and that’s something we have to force ourselves to be careful with.

In a sense, asymmetries are everywhere around us. We live in a world of extreme opinions coming from all sides, extreme actions coming from all sides, and extreme risks and opportunities coming from all sides. Somehow, on aggregate and as a whole, these asymmetries balance each other out, and they keep the world around us pushing forward in a way that is a little more balanced than it was before, even if there are missteps on the way.

As individuals, we have our own asymmetries. We choose our paths over other paths, we pick our people over other people, and we think and believe some things at the expense of other things. These asymmetries are mostly fine, and they generally serve a purpose. That said, the ultimate distinction we see as a whole, the one clearest to us as we look inward or outward is best experienced in a kind of balance rather than as an extreme.

Growth often results in complexity, but if that growth is misbalanced or leans too heavily in one direction, without some kind of punctuation, then sooner or later, that growth tends to destroy itself. As a result, we often have a choice: We can either slowly balance growth on both sides as we evolve, or we can pay the price suddenly, in full, when we push too far.

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