Chapter 2: The Limits of Certainty

What can we know?

The Dream That Wakes You

How do you know you're not dreaming right now?

Think about it. You've had dreams that felt completely real—dreams where you were certain you were awake, certain the events were happening, certain the people were who they seemed to be. Then you woke, and the certainty dissolved. It was all constructed by your sleeping brain.

So: how do you know this isn't one of those dreams? What test could you perform? Pinching yourself won't help—you can dream that you pinch yourself and feel pain. Reading this text doesn't prove anything—you can dream words on a page. The fact that everything seems coherent and continuous only shows that your brain is doing a good job right now, whether waking or dreaming.

Maybe you think this is a silly puzzle—obviously you're awake, obviously you'd know the difference. But would you? The whole point of convincing dreams is that they're convincing. From inside, you can't tell.

This is where epistemology begins: in the gap between how things seem and how things are. We experience the world a certain way, we form beliefs, we feel certain—but feeling certain isn't the same as being right. The history of human thought is littered with certainties that turned out to be false: the earth is flat, the sun goes around the earth, bloodletting cures disease, this group of people is naturally inferior to that group.

So: How do we distinguish knowledge from mere opinion? How do we know when we really know something? What are the sources and limits of human understanding?

These aren't puzzles for philosophers to play with. They're urgent practical questions. When you trust a doctor, vote for a politician, believe what someone tells you, rely on your own judgment—you're betting that you can distinguish reliable belief from unreliable belief. You're betting that you know how to know.

The Greek Doubt: Pyrrho's Strange Peace

Let's begin with a man who took doubt so seriously that he reportedly needed friends to steer him away from cliffs and oncoming carts.

Pyrrho of Elis (c. 360-270 BCE) was a painter who turned philosopher, and he traveled with Alexander the Great's army to India. There, according to ancient sources, he encountered the gymnosophists—the "naked philosophers" who were probably Hindu ascetics or Jain monks. What he saw and discussed with them changed him.

Pyrrho returned to Greece with a strange teaching: on any matter, equally good arguments can be made on all sides. The way things appear to us is not the way things are in themselves. And since we can never access how things really are—only how they seem—the rational response is epochē: suspension of judgment.

This sounds paralyzing. If you can't know anything, how do you live? But Pyrrho wasn't paralyzed. He was, by all accounts, remarkably calm. The suspension of judgment wasn't a problem to solve but a liberation to embrace. When you stop grasping for certainty, stop insisting that you know how things really are, stop fighting against the uncertainty that's actually your condition—you find peace. Ataraxia, the Greeks called it: untroubled tranquility.

The Pyrrhonian skeptics who followed developed this into a sophisticated practice. They didn't claim to know that knowledge is impossible (that would be a knowledge claim). They simply kept investigating, kept finding that every argument could be countered, kept suspending judgment—and kept living, following appearances and customs without claiming they represented truth.

The insight that's easy to miss: Pyrrhonian skepticism isn't nihilism. Pyrrho didn't say nothing matters; he said we should stop tormenting ourselves with unanswerable questions about ultimate truth. You can still act—you follow appearances, conventions, the body's needs, the skills you've developed. You just stop claiming privileged access to reality.

And there's something deeply honest about this. Most of what we call "knowledge" is really confident belief. We don't have certainty; we have degrees of confidence. The Pyrrhonian is just more explicit about this than the rest of us.

The Eastern Connection

Here's where the historical gets interesting. Those Indian philosophers Pyrrho met—what might they have taught him?

We can't know for sure, but the parallels are striking. Buddhist philosophy, which was flourishing in India during Pyrrho's visit, includes sophisticated skeptical arguments. The Madhyamaka school, developed later by Nagarjuna, uses a method remarkably similar to Pyrrhonian skepticism: take any position, show that it leads to contradiction, and thereby dissolve attachment to views. The goal, as with Pyrrho, isn't just intellectual—it's therapeutic. Clinging to views causes suffering; letting go of views brings freedom.

Did Buddhism influence Pyrrho? Did Pyrrho influence later Buddhist developments? Scholars argue, and we'll probably never know. But the parallel itself is significant: two traditions, encountering each other at the edge of their worlds, both developing practices of doubt as a path to peace.

This should give us pause. Skepticism isn't just a Western philosophical game. It's a human response to the recognition that our certainties might be wrong. When that recognition is taken seriously—lived, practiced, embodied—something shifts. The anxious grasping for solid ground relaxes. You learn to swim instead of searching for a floor.

The Indian Map: Ways of Knowing

But now let's complicate the picture. Not all Indian philosophers were skeptics. In fact, Indian philosophy produced some of the most sophisticated epistemological theories in history—systematic accounts of how knowledge is possible and what makes it reliable.

The Pramanas: Valid Means

The Sanskrit term is pramana: a valid means of knowledge, a way of getting at truth. Different Indian schools proposed different lists, but most agreed on at least two: perception (pratyaksha) and inference (anumana).

Perception is direct acquaintance with an object through the senses. You see the fire; you know there's fire. Inference is reasoning from what you perceive to what you don't directly perceive. You see smoke on a distant hill; you infer there's fire you can't see.

So far, this maps onto Western epistemology fairly well. But here's where Indian thought gets interesting: many schools accepted shabda—verbal testimony—as a third, independent source of knowledge.

In the West, if I tell you something, you might believe me, but your knowledge (if any) is based on your judgment of my reliability. The testimony is evidence, not a direct source of knowledge. But for many Indian philosophers, testimony from a reliable source (apta) is itself a pramana—a valid way of knowing, not reducible to perception or inference.

Why does this matter? Because it changes the epistemological game. If testimony is a valid source of knowledge, then the Vedas—accepted as reliable by Hindu schools—can ground genuine knowledge. Revelation isn't second-class knowing that needs to be justified by reason. It's a direct source, on par with perception and inference, though operating in different domains.

This is a radically different epistemological landscape. In the modern West, we tend to assume that individual reason is the ultimate arbiter: you should only believe what you can verify for yourself or infer from what you've verified. But this assumption isn't universal. Many traditions—Indian, African, Islamic, Indigenous—take communally transmitted knowledge as genuinely authoritative, not just as data for individual judgment.

Dignaga's Revolution

Within Indian philosophy, there were debates. The Buddhist epistemologists—most importantly Dignaga (c. 480-540 CE) and his successor Dharmakirti—pushed back against accepting testimony as an independent pramana. They argued that ultimately, only perception and inference are valid sources of knowledge.

But Dignaga was no simple empiricist. He developed sophisticated analyses of perception (only the pure, unconceptualized moment of sensory contact is truly perception—everything else involves interpretation) and inference (which requires universals, which requires an account of how universals relate to particulars). His work influenced both Buddhist and Hindu philosophy for centuries and contains insights that Western epistemologists would later discover independently.

The Buddhist epistemological tradition is rigorous, technical, and demanding—as sophisticated as anything in the Western tradition. It deserves to be better known. And its practitioners were motivated not by abstract puzzle-solving but by the practical goal of liberation: right knowledge helps you see reality clearly, which helps you let go of the attachments that cause suffering.

The Puzzle of Testimony

Let's stay with this question of testimony, because it opens onto something deep.

The Western Suspicion

Modern Western epistemology, especially since Descartes, has been suspicious of testimony. Descartes' method was to doubt everything he could doubt, stripping away all beliefs until he found something indubitable. And what he found was his own existence as a thinking thing: cogito ergo sum. From this foundation, he tried to rebuild knowledge piece by piece, using reason alone.

This exemplifies what we might call the "individual reason" paradigm. Knowledge is what an individual can verify or validly infer. Tradition, authority, community—these are merely sources of opinion that might or might not be reliable. True knowledge is what you can establish for yourself.

There's something noble about this. It's anti-authoritarian, emancipatory. It says: don't just accept what you're told; think for yourself. The Enlightenment extended this into a whole program: subject every belief to the tribunal of reason; throw off the shackles of tradition and superstition; dare to know.

But there's a problem. Almost everything you think you know, you learned from others. You didn't verify that the earth goes around the sun; you trusted your teachers. You didn't confirm that there was a World War II; you trusted books and testimonies. You can't even be sure your own memories are reliable—much of what you "remember" is reconstruction and confabulation.

If we really required individual verification for knowledge, we'd know almost nothing.

The Communal Alternative

Many traditions never shared the Western suspicion of testimony.

In traditional African epistemology, oral testimony is a central and respected way of knowing. Knowledge is held and transmitted by communities—through elders, through griots, through carefully preserved traditions. This isn't blind acceptance; there are criteria for reliable testimony, skills of memory and transmission that are cultivated over generations. But the individual is not the sole arbiter of truth. Knowledge is communal property, held in trust.

Indigenous traditions often share this emphasis. Knowledge of place, of plants, of seasons, of proper relationship—this knowledge is transmitted across generations through story, ceremony, and apprenticeship. The individual learner doesn't verify each claim independently. They enter a tradition, learn to perceive and act in the ways the tradition teaches, and in turn transmit what they've received.

In Islamic philosophy, naql (transmitted knowledge, including revelation) stands alongside 'aql (reason) as a source of knowledge. The Quran is accepted as divine communication, not because reason can prove every claim but because it comes from a reliable source—the most reliable possible source. Faith and reason cooperate; reason helps interpret revelation, but revelation discloses truths that reason alone couldn't reach.

Here's the epistemological question these traditions raise: Is knowledge fundamentally individual or communal? Is the rational individual the ultimate authority, or is knowledge something we hold together, transmitted through trust, embedded in practices and relationships?

The Western Enlightenment bet on the individual. But that bet has costs. It can devalue wisdom traditions that don't fit the verification model. It can lead to an atomized epistemological landscape where everyone is their own authority, unable to trust or learn from others. It can mask the fact that even "individual" reasoners are formed by communities, traditions, and inherited assumptions they've never examined.

Maybe knowledge is more like a commons than a private possession. Maybe "thinking for yourself" isn't possible without first being thought into existence by others.

Many-Sided Truth

Some traditions challenge the very idea of single, definitive truth—not through skeptical doubt but through a recognition of perspective.

Jain Anekantavada: The Doctrine of Many-Sidedness

The Jains of India developed a remarkable epistemological framework. Anekantavada (literally "non-one-sidedness") holds that reality is complex, many-sided, and can be perceived from multiple valid perspectives—none of which captures the whole.

The classic Jain illustration is the blind men and the elephant (a story found across Indian traditions, including in Buddhist Jataka tales). One touches the leg and says, "An elephant is like a pillar." Another touches the trunk and says, "An elephant is like a snake." Another touches the ear and says, "An elephant is like a fan." Each is partly right—their experience is genuine. Each is also limited—they're not experiencing the whole.

For the Jains, this isn't a sad fact about human limitation. It's a positive epistemological principle. Any claim, precisely stated, is a partial truth. Asserting it absolutely, as if it were the whole truth, is a kind of violence—himsa. Nonviolence (ahimsa) in thought means holding your views with humility, recognizing that other perspectives have their own validity.

The Jains developed sophisticated logical tools for expressing this. Syadvada, the "doctrine of maybe," holds that any proposition should be prefaced with syat ("in some respect" or "perhaps"). In some respect, the jar exists. In some respect, the jar does not exist. In some respect, the jar both exists and does not exist. These aren't contradictions; they're recognitions that reality has multiple aspects that require multiple, nonexclusive descriptions.

This isn't relativism in the lazy sense—"everyone's opinion is equally valid, there's no truth." The Jains were rigorous. They thought some views were more adequate than others, some perspectives revealed more of reality. But even the best perspective is still a perspective, not a god's-eye view of how things simply are.

Zhuangzi's Shifting

We met Zhuangzi in Chapter 1, dreaming of butterflies. His perspectivism is wild, playful, and philosophically serious.

Throughout the Zhuangzi, positions are introduced, argued, and then dissolved. A character makes a claim; another character refutes it; then the refutation is refuted; then someone asks whether any of this applies at all. The reader is left dizzy, unable to grasp a stable conclusion.

This is the point. Zhuangzi isn't arguing for a position; he's demonstrating that all positions are positions—perspectives taken up from particular places, useful for certain purposes, but never the final word.

One famous passage, in Brook Ziporyn's translation: "A sage harmonizes with both right and wrong and rests in Heaven's Equality. This is called walking two roads at once."

Zhuangzi doesn't say there's no difference between right and wrong. He says the sage can hold both perspectives without being captured by either. Like the Jain recognizing that the elephant is both like a pillar and like a snake, the Zhuangzian sage moves freely among perspectives, using each when useful, attached to none.

Standpoint Today

This perspectival thinking has modern echoes.

Feminist epistemologists developed "standpoint theory": the claim that knowledge is shaped by social position, and that marginalized standpoints can reveal aspects of reality that dominant positions obscure. A woman might see sexism that a man doesn't notice—not because she's smarter, but because her position makes certain things visible.

This isn't relativism either. Standpoint theory doesn't say all positions are equal. It says some positions are epistemically advantaged for seeing certain things. The slave understands the master-slave relationship differently than the master does—and perhaps more accurately, because the slave has to understand the master to survive, while the master can afford ignorance about the slave.

The convergence is striking. Across millennia and cultures, thoughtful people have recognized that perspective shapes knowledge, that no perspective is total, and that epistemological humility isn't weakness but wisdom.

Science and Its Limits

Science works—the device you're reading this on proves that. No other method of inquiry has produced anything like its track record. What makes it powerful? Institutionalized skepticism. Science is Pyrrho's insight civilized and operationalized: you don't need certainty to make progress; you need methods for detecting and correcting error.

But science is also limited to what can be observed, measured, and predicted. "Scientism"—the claim that science is the only valid knowledge—is self-refuting (the claim itself can't be tested in a lab) and ignores that science presupposes assumptions it can't prove: that nature is regular, that mathematics applies to the physical world, that the past guides the future. Knowledge-how (riding a bike), interpersonal knowledge (knowing a person), self-knowledge, moral perception, wisdom—science is silent on most of what matters most.

Living With Uncertainty

So where does this leave us? We can't know with certainty that we're not dreaming. Our senses might deceive us. Our reasoning might be flawed. Our traditions might be wrong. Science is powerful but limited. Every perspective is partial. Certainty, it seems, is not on offer.

How do we live with this?

One option: pretend we have certainty anyway. This is what most people do most of the time. It works reasonably well until it doesn't—until the certainties crack and the ground gives way.

Another option: embrace paralysis. If we can't know anything for sure, why try? But this is its own kind of bad faith. You're living anyway. You're acting on beliefs anyway. Refusing to examine them doesn't make them go away.

A third option: learn to hold beliefs with appropriate confidence. Not all beliefs are equally uncertain. That the sun will rise tomorrow is vastly more certain than that your political opinions are correct. That you exist is more certain than that your memories are accurate. Epistemological maturity involves calibrating confidence to evidence—being more sure of what warrants sureness, more tentative about what doesn't.

This is harder than it sounds. We're wired for overconfidence, for mistaking feeling certain with being right. But it can be practiced. You can notice when you're asserting something you haven't really examined. You can catch yourself dismissing evidence that threatens your beliefs. You can cultivate the humility to say "I don't know" and the courage to say "I think" without claiming "I'm certain."

The Pyrrhonian Peace

Here's what Pyrrho discovered, and what contemplatives in many traditions have found: there's a freedom in uncertainty.

Not the anxious uncertainty of someone desperately wanting answers and not finding them. But the peaceful uncertainty of someone who has stopped demanding what reality can't give. You're in the stream—you've always been in the stream—and the search for solid ground was an illusion. Once you stop searching, you can learn to swim.

This doesn't mean giving up inquiry. It means holding inquiry lightly. The questions still matter. The investigations continue. But the anxious grasping—the need to know for sure, to have the truth, to reach the end of questioning—relaxes. And in that relaxation, something opens up: space for genuine curiosity, for the delight of learning, for the ongoing adventure of trying to understand.

You still don't know if you're dreaming. But here's the thing: it doesn't matter as much as you thought. Dreaming or waking, you're having this experience. Dreaming or waking, you can bring attention, care, curiosity to what's in front of you. The uncertainty about foundations doesn't prevent you from building. It just reminds you that all buildings are provisional—and that's okay.

This is the epistemological wisdom that threads through the traditions we've visited: not certainty but appropriate confidence, not absolute truth but adequate truth, not knowledge that ends questioning but knowledge that enables better questioning.

You know enough to continue. Continue.

Going Deeper

Primary Source: How We Know What Isn't So by Thomas Gilovich (Free Press). This isn't a philosophy book but a psychology book about the cognitive biases that lead us astray—why we see patterns that aren't there, why we remember selectively, why we're overconfident. It's epistemology from the empirical side: showing, through research, the specific ways human knowing goes wrong. Start here to understand, concretely, why epistemology matters—why the question "How do we know?" isn't abstract but urgent.

Accessible Secondary: The Problems of Philosophy by Bertrand Russell (Oxford). This short, elegant book from 1912 remains one of the best introductions to epistemology. Russell takes the basic questions seriously—What can we know? How do we know it? What about the external world?—and works through them with clarity and intellectual honesty. He doesn't resolve everything, but he shows you what the problems are and why they matter.

Unexpected Entry: Outlines of Pyrrhonism by Sextus Empiricus, translated by R.G. Bury (Harvard/Loeb). This is the most complete surviving text of ancient Greek skepticism—a practical handbook for suspending judgment and finding peace. It's more demanding than the others, but surprisingly relevant. Sextus anticipated many modern philosophical puzzles, and his therapeutic approach to skepticism offers something purely intellectual treatments miss: a way of living with uncertainty that might actually bring tranquility.