How Do You Know?

In IB Theory of Knowledge, seemingly simple questions lead to some surprisingly lively lessons. Try your hand at a few classroom activities and discover how Edsmen learn to explain not just what they know, but how they know it.

Look closely at the blue dots. Are they moving?

The image is perfectly still. 

Look again. 

Knowing the answer may not stop the movement you seem to see. When knowledge and perception disagree, which gets the last word?

That question gave parents a glimpse into Theory of Knowledge, or TOK, during a recent presentation led by IB Coordinator Simon Masters and Teacher Peter Knittel. The two teach the course, which is required for every candidate in the International Baccalaureate Diploma Program. TOK brings the philosophical study of knowledge—known as epistemology—into everyday life. Students examine how they know what they know, what counts as evidence, and why people can reach different conclusions from the same information.

Consider a game called “Is It Soup?” Students decide which combinations of ingredients, containers, and utensils qualify, then work toward a definition that accounts for their choices.

Give it a try: which of these would you call soup?

Make your choices. Then try to explain the rule behind them.

Does soup need broth? Can it be cold? Do noodles help its case? Does the container matter?

And if your definition is something like “food served in a bowl with liquid,” what happens when someone brings up cereal?

The discussion is funny. It is also doing serious work.

Students who confidently identify a dish as soup must explain why. Their classmates may have equally confident answers built on entirely different definitions. As the examples get stranger, students must decide whether to stand by their rule, make an exception, or start over.

Some of our choices led to rules we didn’t actually agree with—like ‘Soup must have ice in it.’ That made us laugh, but it also made us think about what criteria we use to decide whether something belongs in a category. -Evan Lentz ’28

The goal is to help students make thoughtful judgments and explain why those judgments deserve confidence. That means learning when to trust an answer—and when to take another look.

That awareness is part of the point. Understanding another person’s reasoning requires more than waiting for a turn to disagree. It means considering how someone else arrived at an answer, including the experiences and assumptions that made it seem reasonable.

Soup gives students an accessible place to practice. The questions quickly reach beyond the bowl.

Categories help people organize information and communicate efficiently. But every category has boundaries, and those boundaries reflect choices. In class, Masters asks students to consider a familiar example: the letter grade.

A grade conveys something useful. But how much does it reveal about a student’s understanding? Does it capture the originality of an idea, improvement over time, or a contribution that helped the whole class learn?

Students examine what a measurement tells them, what it leaves out, and what happens when people treat it as the complete picture.

In another lesson, students face a hypothetical cultural emergency: Twenty musical artists will disappear from human culture and memory. Only three can be saved. Who gets to stay?

An artist’s influence might matter. So might musical range, originality, or personal significance. But choosing three names is only the beginning. Students must explain why those qualities should guide the decision.

Then the discussion shifts to basketball: Who is the greatest player of all time?

Here, students readily reach for statistics. Points, records, and championships become evidence. Yet music has numbers, too—sales, streams, and revenue.

Why should numerical evidence carry more weight in one discussion than in another?

The lesson asks students to notice when they change the rules of an argument, sometimes without realizing it. Before defending a conclusion, they need to examine the standards they used to reach it.

That habit carries into their other courses. A historian investigates a document’s origins and reliability. A mathematician constructs a proof. Both seek sound conclusions, but their methods differ. TOK asks students to consider why those approaches work, what they can establish, and where their limits lie.

Knittel identifies intellectual humility as a central goal of the course: recognizing how experience shapes understanding and remaining willing to reconsider. As his presentation puts it, “TOK allows us to take ownership and responsibility for our habits of mind.”

That responsibility connects the course to St. Edward’s Holy Cross identity. Students consider perspectives beyond their own and ask what their knowledge calls them to do in response to the needs and concerns of others.

TOK has helped me look more carefully at the reasoning behind people’s ideas, especially in seminar courses. Even when I disagree, I can try to understand how someone arrived at their point of view. That helps me think through what I believe and why. -August Marcelino ’27

Whether Edsmen are analyzing a business decision, translating a Latin passage, or explaining a chemistry experiment, “How do you know?” asks them to account for their reasoning. A second question carries that inquiry beyond the classroom: What will you do with what you know?