Philosophical Riddles

Our presence in the universe is something too bizarre for words. The mundaneness of our daily lives cause us take our existence for granted — but every once in a while we’re cajoled out of that complacency and enter into a profound state of existential awareness, and we ask: Why is there all this stuff in the universe, and why is it governed by such exquisitely precise laws? And why should anything exist at all? We inhabit a universe with such things as spiral galaxies, the aurora borealis, and SpongeBob Squarepants.

One of the more extraordinary things about the universe is that it has produced beings who can observe it — namely, us.

And as Sean Carroll notes, “Nothing about modern physics explains why we have these laws rather than some totally different laws, although physicists sometimes talk that way — a mistake they might be able to avoid if they took philosophers more seriously.” And as for the philosophers, the best that they can come up with is the anthropic principle— the notion that our particular universe appears the way it does by virtue of our presence as observers within it — a suggestion that has an uncomfortably tautological ring to it.

This the classic Cartesian question. It essentially asks, how do we know that what we see around us is the real deal, and not some grand illusion perpetuated by an unseen force (who René Descartes referred to as the hypothesized ‘evil demon’)? More recently, the question has been reframed as the “brain in a vat” problem, or the Simulation Argument. And it could very well be that we’re the products of an elaborate simulation. A deeper question to ask, therefore, is whether the civilization running the simulation is also in a simulation — a kind of supercomputer regression (or simulation-ception).

What’s more, we may not be who we think we are. Assuming that the people running the simulation are also taking part in it, our true identities may be temporarily suppressed, to heighten the realness of the experience. This philosophical conundrum also forces us to re-evaluate what we mean by “real.” Modal realists argue that if the universe around us seems rational (as opposed to it being dreamy, incoherent, or lawless), then we have no choice but to declare it as being real and genuine. Or maybe, as Cipher said after eating a piece of “simulated” steak in The Matrix, “Ignorance is bliss.”

Also called the dilemma of determinism, we do not know if our actions are controlled by a causal chain of preceding events (or by some other external influence), or if we’re truly free agents making decisions of our own volition. Philosophers (and now some scientists) have been debating this for millennia, and with no apparent end in sight. If our decision making is influenced by an endless chain of causality, then determinism is true and we don’t have free will. But if the opposite is true, what’s called indeterminism, then our actions must be random — what some argue is still not free will.

Conversely, libertarians (no, not political libertarians, those are other people), make the case for compatibilism — the idea that free will is logically compatible with deterministic views of the universe. Compounding the problem are advances in neuroscience showing that our brains make decisions before we’re even conscious of them. But if we don’t have free will, then why did we evolve consciousness instead of zombie-minds? Quantum mechanics makes this problem even more complicated by suggesting that we live in a universe of probability, and that determinism of any sort is impossible.

And as Linas Vepstas has said, “Consciousness seems to be intimately and inescapably tied to the perception of the passage of time, and indeed, the idea that the past is fixed and perfectly deterministic, and that the future is unknowable. This fits well, because if the future were predetermined, then there’d be no free will, and no point in the participation of the passage of time.”

Simply put, we cannot know if God exists or not. Both the atheists and believers are wrong in their proclamations, and the agnostics are right. True agnostics are simply being Cartesian about it, recognizing the epistemological issues involved and the limitations of human inquiry. We do not know enough about the inner workings of the universe to make any sort of grand claim about the nature of reality and whether or not a Prime Mover exists somewhere in the background. Many people defer to naturalism — the suggestion that the universe runs according to autonomous processes — but that doesn't preclude the existence of a grand designer who set the whole thing in motion (what's called deism). And as mentioned earlier, we may live in a simulation where the hacker gods control all the variables. Or perhaps the gnostics are right and powerful beings exist in some deeper reality that we're unaware of. These aren't necessarily the omniscient, omnipotent gods of the Abrahamic traditions — but they're (hypothetically) powerful beings nonetheless. Again, these aren't scientific questions per se — they're more Platonic thought experiments that force us to confront the limits of human experience and inquiry.

Before everyone gets excited, this is not a suggestion that we'll all end up strumming harps on some fluffy white cloud, or find ourselves shoveling coal in the depths of Hell for eternity. Because we cannot ask the dead if there's anything on the other side, we're left guessing as to what happens next. Materialists assume that there's no life after death, but it's just that — an assumption that cannot necessarily be proven. Looking closer at the machinations of the universe (or multiverse), whether it be through a classical Newtonian/Einsteinian lens, or through the spooky filter of quantum mechanics, there's no reason to believe that we only have one shot at this thing called life. It's a question of metaphysics and the possibility that the cosmos (what Carl Sagan described as 'all that is or ever was or ever will be') cycles and percolates in such a way that lives are infinitely recycled. Hans Moravec put it best when, speaking in relation to the quantum Many Worlds Interpretation, said that non-observance of the universe is impossible; we must always find ourselves alive and observing the universe in some form or another. This is highly speculative stuff, but like the God problem, is one that science cannot yet tackle, leaving it to the philosophers.

There's a difference between understanding the world objectively (or at least trying to, anyway) and experiencing it through an exclusively objective framework. This is essentially the problem of qualia — the notion that our surroundings can only be observed through the filter of our senses and the cogitations of our minds. Everything you know, everything you've touched, seen, and smelled, has been filtered through any number of physiological and cognitive processes. Subsequently, your subjective experience of the world is unique. In the classic example, the subjective appreciation of the color red may vary from person to person. The only way you could possibly know is if you were to somehow observe the universe from the 'conscious lens' of another person in a sort of Being John Malkovich kind of way — not anything we're likely going to be able to accomplish at any stage of our scientific or technological development. Another way of saying all this is that the universe can only be observed through a brain (or potentially a machine mind), and by virtue of that, can only be interpreted subjectively. But given that the universe appears to be coherent and (somewhat) knowable, should we continue to assume that its true objective quality can never be observed or known? It's worth noting that much of Buddhist philosophy is predicated on this fundamental limitation (what they call emptiness), and a complete antithesis to Plato's idealism.

Essentially, we'll never truly be able to distinguish between 'right' and 'wrong' actions. At any given time in history, however, philosophers, theologians, and politicians will claim to have discovered the best way to evaluate human actions and establish the most righteous code of conduct. But it's never that easy. Life is far too messy and complicated for there to be anything like a universal morality or an absolutist ethics. The Golden Rule is great (the idea that you should treat others as you would like them to treat you), but it disregards moral autonomy and leaves no room for the imposition of justice (such as jailing criminals), and can even be used to justify oppression (Immanuel Kant was among its most staunchest critics). Moreover, it's a highly simplified rule of thumb that doesn't provision for more complex scenarios. For example, should the few be spared to save the many? Who has more moral worth: a human baby or a full-grown great ape? And as neuroscientists have shown, morality is not only a culturally-ingrained thing, it's also a part of our psychologies (the Trolly Problem is the best demonstration of this). At best, we can only say that morality is normative, while acknowledging that our sense of right and wrong will change over time.

We use numbers every day, but taking a step back, what are they, really — and why do they do such a damn good job of helping us explain the universe (such as Newtonian laws)? Mathematical structures can consist of numbers, sets, groups, and points — but are they real objects, or do they simply describe relationships that necessarily exist in all structures? Plato argued that numbers were real (it doesn't matter that you can't 'see' them), but formalists insisted that they were merely formal systems (well-defined constructions of abstract thought based on math). This is essentially an ontological problem, where we're left baffled about the true nature of the universe and which aspects of it are human constructs and which are truly tangible.

Suppose someone tells you “I am lying.” If what she tells you is true, then she is lying, in which case what she tells you is false. On the other hand, if what she tells you is false, then she is not lying, in which case what she tells you is true. In short: if “I am lying” is true then it is false, and if it is false then it is true. The paradox arises for any sentence that says or implies of itself that it is false (the simplest example being “This sentence is false”). It is attributed to the ancient Greek seer Epimenides (fl. c. 6th century BCE), an inhabitant of Crete, who famously declared that “All Cretans are liars” (consider what follows if the declaration is true). The paradox is important in part because it creates severe difficulties for logically rigorous theories of truth; it was not adequately addressed (which is not to say solved) until the 20th century.

In the 5th century BCE, Zeno of Elea devised a number of paradoxes designed to show that reality is single (there is only one thing) and motionless, as his friend Parmenides had claimed. The paradoxes take the form of arguments in which the assumption of plurality (the existence of more than one thing) or motion are shown to lead to contradictions or absurdity. Here are two of the arguments: Against plurality: (A) Suppose that reality is plural. Then the number of things there are is only as many as the number of things there are (the number of things there are is neither more nor less than the number of things there are). If the number of things there are is only as many as the number of things there are, then the number of things there are is finite. (B) Suppose that reality is plural. Then there are at least two distinct things. Two things can be distinct only if there is a third thing between them (even if it is only air). It follows that there is a third thing that is distinct from the other two. But if the third thing is distinct, then there must be a fourth thing between it and the second (or first) thing. And so on to infinity. (C) Therefore, if reality is plural, it is finite and not finite, infinite and not infinite, a contradiction. Against motion: Suppose that there is motion. Suppose in particular that Achilles and a tortoise are moving around a track in a foot race, in which the tortoise has been given a modest lead. Naturally, Achilles is running faster than the tortoise. If Achilles is at point A and the tortoise at point B, then in order to catch the tortoise Achilles will have to traverse the interval AB. But in the time it takes Achilles to arrive at point B, the tortoise will have moved on (however slowly) to point C. Then in order to catch the tortoise, Achilles will have to traverse the interval BC. But in the time it takes him to arrive at point C, the tortoise will have moved on to point D, and so on for an infinite number of intervals. It follows that Achilles can never catch the tortoise, which is absurd. Zeno’s paradoxes have posed a serious challenge to theories of space, time, and infinity for more than 2,400 years, and for many of them there is still no general agreement about how they should be solved.

Also called “the heap,” this paradox arises for any predicate (e.g., “… is a heap”, “… is bald”) whose application is, for whatever reason, not precisely defined. Consider a single grain of rice, which is not a heap. Adding one grain of rice to it will not create a heap. Likewise adding one grain of rice to two grains or three grains or four grains. In general, for any number N, if N grains does not constitute a heap, then N+1 grains also does not constitute a heap. (Similarly, if N grains does constitute a heap, then N-1 grains also constitutes a heap.) It follows that one can never create a heap of rice from something that is not a heap of rice by adding one grain at a time. But that is absurd. Among modern perspectives on the paradox, one holds that we simply haven’t gotten around to deciding exactly what a heap is (the “lazy solution”); another asserts that such predicates are inherently vague, so any attempt to define them precisely is wrongheaded.

Although it bears his name, the medieval philosopher Jean Buridan did not invent this paradox, which probably originated as a parody of his theory of free will, according to which human freedom consists in the ability to defer for further consideration a choice between two apparently equally good alternatives (the will is otherwise compelled to choose what appears to be the best). Imagine a hungry donkey who is placed between two equidistant and identical bales of hay. Assume that the surrounding environments on both sides are also identical. The donkey cannot choose between the two bales and so dies of hunger, which is absurd. The paradox was later thought to constitute a counterexample to Leibniz’s principle of sufficient reason, one version of which states that there is an explanation (in the sense of a reason or cause) for every contingent event. Whether the donkey chooses one bale or the other is a contingent event, but there is apparently no reason or cause to determine the donkey’s choice. Yet the donkey will not starve. Leibniz, for what it is worth, vehemently rejected the paradox, claiming that it was unrealistic.

A teacher announces to her class that there will be a surprise test sometime during the following week. The students begin to speculate about when it might occur, until one of them announces that there is no reason to worry, because a surprise test is impossible. The test cannot be given on Friday, she says, because by the end of the day on Thursday we would know that the test must be given the next day. Nor can the test be given on Thursday, she continues, because, given that we know that the test cannot be given on Friday, by the end of the day on Wednesday we would know that the test must be given the next day. And likewise for Wednesday, Tuesday, and Monday. The students spend a restful weekend not studying for the test, and they are all surprised when it is given on Wednesday. How could this happen? (There are various versions of the paradox; one of them, called the Hangman, concerns a condemned prisoner who is clever but ultimately overconfident.) The implications of the paradox are as yet unclear, and there is virtually no agreement about how it should be solved.

You buy a lottery ticket, for no good reason. Indeed, you know that the chance that your ticket will win is at least 10 million to one, since at least 10 million tickets have been sold, as you learn later on the evening news, before the drawing (assume that the lottery is fair and that a winning ticket exists). So you are rationally justified in believing that your ticket will lose—in fact, you’d be crazy to believe that your ticket will win. Likewise, you are justified in believing that your friend Jane’s ticket will lose, that your uncle Harvey’s ticket will lose, that your dog Ralph’s ticket will lose, that the ticket bought by the guy ahead of you in line at the convenience store will lose, and so on for each ticket bought by anyone you know or don’t know. In general, for each ticket sold in the lottery, you are justified in believing: “That ticket will lose.” It follows that you are justified in believing that all tickets will lose, or (equivalently) that no ticket will win. But, of course, you know that one ticket will win. So you’re justified in believing what you know to be false (that no ticket will win). How can that be? The lottery constitutes an apparent counterexample to one version of a principle known as the deductive closure of justification: If one is justified in believing P and justified in believing Q, then one is justified in believing any proposition that follows deductively (necessarily) from P and Q. For example, if I am justified in believing that my lottery ticket is in the envelope (because I put it there), and if I am justified in believing that the envelope is in the paper shredder (because I put it there), then I am justified in believing that my lottery ticket is in the paper shredder. Since its introduction in the early 1960s, the lottery paradox has provoked much discussion of possible alternatives to the closure principle, as well as new theories of knowledge and belief that would retain the principle while avoiding its paradoxical consequences.

This ancient paradox is named for a character in Plato’s eponymous dialogue. Socrates and Meno are engaged in a conversation about the nature of virtue. Meno offers a series of suggestions, each of which Socrates shows to be inadequate. Socrates himself professes not to know what virtue is. How then, asks Meno, would you recognize it, if you ever encounter it? How would you see that a certain answer to the the question “What is virtue?” is correct, unless you already knew the correct answer? It seems to follow that no one ever learns anything by asking questions, which is implausible, if not absurd. Socrates’ solution is to suggest that basic elements of knowledge, enough to recognize a correct answer, can be “recollected” from a previous life, given the right kind of encouragement. As proof he shows how a slave boy can be prompted to solve geometrical problems, though he has never had instruction in geometry. Although the recollection theory is no longer a live option (almost no philosophers believe in reincarnation), Socrates’ assertion that knowledge is latent in each individual is now widely (though not universally) accepted, at least for some kinds of knowledge. It constitutes an answer to the modern form of Meno’s problem, which is: how do people successfully acquire certain rich systems of knowledge on the basis of little or no evidence or instruction? The paradigm case of such “learning” (there is debate about whether “learning” is the correct term) is first-language acquisition, in which very young (normal) children manage to acquire complex grammatical systems effortlessly, despite evidence that is completely inadequate and often downright misleading (the ungrammatical speech and erroneous instruction of adults). In this case, the answer, originally proposed by Noam Chomsky in the 1950s, is that the basic elements of the grammars of all human languages are innate, ultimately a genetic endowment reflecting the cognitive evolution of the human species.

Suppose you are sitting in a windowless room. It begins to rain outside. You have not heard a weather report, so you don’t know that it’s raining. So you don’t believe that it’s raining. Thus your friend McGillicuddy, who knows your situation, can say truly of you, “It’s raining, but MacIntosh doesn’t believe it is.” But if you, MacIntosh, were to say exactly the same thing to McGillicuddy—“It’s raining, but I don’t believe it is”—your friend would rightly think you’d lost your mind. Why, then, is the second sentence absurd? As G.E. Moore put it, “Why is it absurd for me to say something true about myself?” The problem Moore identified turned out to be profound. It helped to stimulate Wittgenstein’s later work on the nature of knowledge and certainty, and it even helped to give birth (in the 1950s) to a new field of philosophically inspired language study, pragmatics. I’ll leave you to ponder a solution.

The Hotel Infinity paradox is used to explain the concept of infinity. Picture a hotel in your mind. Try to imagine that this room has an infinite number of rooms with an infinite number of guests staying in them. Now, imagine you walked up to the reception and asked for a room. Unfortunately, the infinite rooms are full of infinite guests, meaning there is no room at the inn for you. Luckily, the desk manager has a brainwave. He says: “I’ve got it. I’ll just move the guest in Room 1 to Room 2!” And he does. He moves the guest that was in Room 2 to Room 3, and Room 3 to Room 4, and so on—an infinite number of guests getting bumped deeper into the infinite number of rooms. This seems perfectly reasonable. However, the hotel originally had an infinite number of guests and now it has infinity plus one. So which number is really infinity?

Ludwig Wittgenstein (1889 –1951) was an Austrian-British philosopher. He published his book Philosophical Investigations in 1953, and it has since come to be recognized as one of the most important works of philosophy in the twentieth century. Wittgenstein was also the author of the famous beetle in the box thought experiment. For this thought experiment, Wittgenstein asks that we imagine a group of people who each have a box containing something called a “beetle”. No one can see into anyone else’s box. Everyone is asked to describe their beetle, but each person can only talk about their own beetle, as there might be different things in each person’s box. Over time, the word “beetle” simply comes to mean “that thing that is in a person’s box.” The mental experiment makes us think about how we describe our unique experiences. The beetle is like our minds. We can never know exactly what other people are experiencing. So, if someone says they are experiencing pain or love, we can never really know what that experience is like for them and whether it is the same for us.

One of the most well-known ethical thought experiments is the Trolley Problem. This experiment was recently used to dramatic effect in the TV series The Good Place. The experiment goes like this: Imagine you are driving a trolley and the brakes fail. Up ahead are five people tied to the trolley tracks. You can choose to switch your trolley to another track. However, this track has one person tied to it. You are now in a moral dilemma. If you do nothing, five people will die. However, if you take action to save those five people, your deed will lead to the death of an innocent person. This could be one of the hardest philosophical questions to answer.

The Experience Machine is a thought experiment put forward by philosopher Robert Nozick in his 1974 book Anarchy, State, and Utopia. Suppose there was an experience machine that would give you any experience you desired. You can choose whatever experiences you want to have by pre-programming the machine. Once in the machine, your brain would be stimulated so that it felt like you were experiencing everything you had programmed. You would not know that these experiences weren’t real. For you, they would seem just like ordinary life. Plugging into the machine would eliminate toil, struggle and suffering and create a life of perfection. Would you plug in? Many people would choose not to because this perfect life would not be ‘real’. But what would the difference be?

One of the oldest of all thought experiments is the paradox known as the Ship of Theseus, which originated in the writings of Plutarch. In this philosophical question, you are asked to imagine a ship that has remained seaworthy for hundreds of years due to constant repairs. As soon as one plank became old and rotted, it would be replaced, and so on until every working part of the ship was no longer original. The question is whether this ship is still the same Ship of Theseus, or something completely different. If it’s not the same ship, at what point did it become something new? You could say the same for a person as each of our cells regenerates to the point that nothing left of the person we were when we were born remains. Does this mean we are a totally different person? If not, what is it that makes us the same person throughout our lives? At its heart, the experiment forces one to question the commonly held idea that identity is solely contained in physical objects and phenomena.