Part 1

Objective truth doesn’t exist.

Many of us, especially those who prize rationalism and objectivity, cling to the idea of truth. We think there is a correct answer to every problem. Let’s take it a bit further: there is exactly one correct answer to every dilemma. Let’s take it even just a bit further:

Theorem 1. There exists an objective truth independent of any individual or cultural elements. Furthermore, there cannot be more than one objective truth.

That correct answer might be hidden, whether in reams of equations or a mess of socioeconomic dynamics, but it exists. The goal, then, should be to get to the truth, leaving all personal biases at the door.

This is the common-sense perspective. This is the accepted view. After all, how did I lose 1% on my physics exam if objective truth doesn’t exist? These ideas can be traced back to Plato (and probably before too). In his Theory of Forms, Plato considered our material world as a flawed representation of the “real” world. This world is the world of Forms: abstract objects that can only be understood through pure reason, free of the fickle human senses.

This is a quintessential example of what Nietzsche — whose ideas are the subject of this article — would call “true-world theories”. They come in various forms, but they all suggest that the world we directly experience is not the real world, and there is another truer world for which we should devote our finite time.

Nietzsche argues that there is an escape from the burden of nihilism in the form of true world theories. They satisfy two human desires: the desire for life to have meaning, and self-esteem. I could explain both, but Nietzsche puts it better than I ever could:

“It granted man an absolute value, as opposed to his smallness and accidental occurrence in the flux of becoming and passing away” (Friedrich Nietzsche, The Will to Power)

One of the most common true world theories is Christianity, which actually takes many inspirations from Platonic ideas. For example, the idea of the eternal soul that persists after death was one of the hallmarks of Plato’s philosophy.

However, with the Scientific Revolution, Nietzsche thought that we, as a society, had made the existence of God impossible. This is the source of his arguably most quoted lines:

God is dead. God remains dead. And we have killed him. How shall we comfort ourselves, the murderers of all murderers?… Is not the greatness of this deed too great for us? Must we ourselves not become gods simply to appear worthy of it? (Friedrich Nietzsche, The Gay Science)

This was written in 1882. I’d argue that we still haven’t had the crisis Nietzsche predicted.

Christian values had formed, and continue to form, the basis for nearly all Western ethical systems, which spread worldwide through colonialism.

There are so many conclusions and ideas that can be drawn from this, but I want to tie this back to the idea of objective truth. Nietzche argued that the death of God would lead to the loss of objective truth. He argued that knowledge was fluid, based on perspectives or interests. This view is called perspectivism. I got that one from Wikipedia, so take it as you will.

Part B

So! Objective truth doesn’t exist. Our answers to questions will forever be tainted by our personal, cultural and psychological biases. This applies both to individuals and society as a whole.

Now consider this: what day is it today? There is only one correct answer to this, but it depends on when you’re reading it. Thus the ambiguity comes not in the answer, but in the question itself. To remove it, we might say: “Assuming that it is September 26, 2020, what day is it today?” This statement removes the ambiguity, but in the spirit of Nietzsche let’s keep questioning. What is a day? Where did days start? Are we using the Gregorian calendar? All of these questions could, in theory, be answered, but their answers would each be culturally motivated, and thus not objective.

This line of questioning could be brought up against anything, but most of them have answers, however arbitrary. By making some foundational assumptions, we can then represent objective realities by building on top of those assumptions. Mathematics is a good example. If we hold the rules of mathematics to be true, then we can build numerical representations of reality. Physics is a good example — using the language of mathematics we can formulate theories of reality. The theory of gravity operates regardless of historical or cultural context, regardless of the cultural context that led to its development and representation.

The primary thing that limits knowledge, in my opinion, is applicability. The scope of a certain answer is what dictates how objective something is. The idea that it’s rude to chew with your mouth open is only applicable in narrow cultural contexts, while gravity applies in a far wider context. The death of God removes the universal truths of the Christian moral doctrine (which formed the bedrock of society for 1000+ years), limiting its applicability and thus its subjective objectivity (that’s a mouthful).

Part III

So the death of God, as discussed by Nietzsche, has limited the applicability of Christian-based truths, thus making them more subjective. Applicability dictates how objective/subjective a piece of knowledge is. This begs the question: is there an objective truth that is applicable to the entire universe?

In the history of science we have discovered a sequence of better and better theories or models, … It is natural to ask: Will this sequence eventually reach an end point, an ultimate theory of the universe, that will include all forces and predict every observation we can make, or will we continue forever finding better theories, but never one that cannot be improved upon? (Stephen Hawking and Leonard Mlodinow, The Grand Design)

This marks the shift of this article from philosophy to physics. The great quest of physics since Newton’s Principia has been to find a theory that can describe the entire universe. Spoiler alert: it’s probably not possible.

Consider doing a ball-drop experiment on a flying plane. A ball is dropped from rest from a fixed height. An observer on the plane would say that between two times, the ball did not move horizontally, and it thus has no horizontal velocity. An observer on solid ground wouldn’t agree, arguing that the ball moved a very large distance horizontally. An observer from the moon would disagree again, and so on. All the observers are using different frames of reference, so who’s right?

The answer, frustrating as it is, is all of them. No observer can accurately argue against the others. We thus adopt the idea of model-dependent realism, a term coined by Stephen Hawking and Leondard Mlodinow:

A physical theory or world picture is a model (generally of a mathematical nature) and a set of rules that connect the elements of the model to observations. (Hawking & Mlodinow, The Grand Design)

This is the crux of this article. We can’t point to a single physical reality because it depends on the observer. If we go deeper into quantum physics (liberally simplified) we find that the universe doesn’t have a definite history. If we go further, we find that time, as we know it, didn’t have a beginning.

These ideas are covered in depth in The Grand Design, which I highly suggest you read. I need to stress that I’m not an expert, nor are these ideas as simple as I’m making them out to be. What I’ve talked about is only a fraction of the ideas covered in the book. That said, I hope you liked this intersection between philosophy and physics:) Nietzsche had a lot of ideas, I leave the research of the rest of them to you. Here’s my personal favourite Nietzsche quote:

[Nobody has] ever looked into the world with a distrust as deep, seeming, as I do, not simply the timely advocate of the devil, but, to employ theological terms, an enemy and challenger of God.