No. There are no modules, no deadlines and no certificate. It is a reference and a set of tools — use it in the order that matches what you are curious about. If you want a structured introduction, the Ship of Theseus guide is a good first step.

What level does it assume?

Every guide states its level: Beginner, Intermediate or Advanced. Start with Beginner guides and move up when you want more detail. The Philosophy Basics site is a useful companion if you want more introductory context.

Are the quotes sourced?

Yes. Every quote states the work and passage it comes from. We also note lines that are commonly misattributed. The Project Gutenberg library hosts many primary texts for free, and the Stanford Encyclopedia of Philosophy is the authoritative academic reference.

Are the tools private?

Yes. The Argument Mapper, Fallacy Finder and Thought Experiment Lab all run in your browser. Nothing you type is sent anywhere. They use no cookies and no analytics.

Where can I read primary texts for free?

Project Gutenberg hosts thousands of philosophy texts whose copyright has expired. Perseus Digital Library offers Greek and Latin texts with translations. For contemporary philosophy, many authors post working papers on PhilArchive.

Is there a recommended reading order?

There is no single correct order, but most people find it helpful to start with a branch that matches a live question they have — ethics if you face a moral dilemma, epistemology if you are thinking about what you can know. The Reading Path Builder tool (coming soon) will suggest an order based on your interests.

How do you decide what to cover?

We prioritise questions that are most searched, most debated and most relevant to everyday decisions. We also follow the PhilPapers Survey to see which positions professional philosophers actually hold, so we can represent live debates rather than outdated textbook summaries.

A guide to the big questions

Think clearly about
what matters.

Plain-language guides to 2,600 years of ideas, with tools for building arguments, spotting bad reasoning and finding what to read next.

6 core branches

2,600 years of ideas

[N] guides and growing

Each layer rests on the one below it.

Layer 03 of 05

Metaphysics

The study of the fundamental nature of reality: what exists, what time is, how mind relates to body, and whether free will is possible.

Where you meet it: Thinking about consciousness, identity, or why there is something rather than nothing.

A teaching illustration. Philosophers disagree on which branch is foundational.

Branches

Pick the question that
bothers you most.

Every branch starts from one stubborn question. Each has its own hub of guides, thinkers and key terms.

Metaphysics What is real? Existence, time, causation, mind and body, free will. Epistemology How do we know? Knowledge, belief, evidence, doubt and the limits of certainty. Ethics How should we live? Right and wrong, duty, consequences, character and the good life. Logic What follows from what? Valid arguments, proofs, paradoxes and common fallacies. Aesthetics What is beautiful? Art, beauty and why some things move us. Political philosophy What is a just society? Justice, liberty, rights, power and the social contract.

Tools

Philosophy you
can practise.

Tools for students writing essays, teachers planning lessons and anyone who wants to reason better at work.

Argument Mapper. Lay out premises and a conclusion, then test its validity.
Fallacy Finder. Practise naming the flaw in everyday reasoning.
Thought Experiment Lab. Make a choice and see which tradition you sided with.
Thinker Compare. Two philosophers side by side on one question.
Reading Path Builder. A reading order matched to your level and time.
Glossary. Terms like "a priori" explained in one sentence.

Example: the classic syllogism

P1 All humans are mortal.

P2 Socrates is a human.

∴ C

✓ Valid: the conclusion follows from the premises. Sound: check that the premises are true.

Open full tool

Identify the fallacy in the example below.

Everyone in my office believes homeopathy works, so it must be effective.

Open full tool

The trolley problem

A runaway trolley heads toward five people. You can pull a lever to divert it to a track where one person is tied. Do you pull?

Open full tool

Ideas in data

See the shape of the subject.

When they lived

600 BCE 700 CE 2000 CE

Confucius

551 BCE – 479 BCE

Socrates

470 BCE – 399 BCE

Aristotle

384 BCE – 322 BCE

Augustine

354 CE – 430 CE

Aquinas

1225 CE – 1274 CE

Kant

1724 CE – 1804 CE

de Beauvoir

1908 CE – 1986 CE

Ancient dates are approximate. Source: standard biographical references.

What philosophers believe today

Share who accept or lean toward each view. PhilPapers Survey, 2020.

NORMATIVE ETHICS

Virtue ethics

37%

Deontology

32%

Consequentialism

31%

FREE WILL

Compatibilism

59%

Libertarianism

17%

No free will

12%

Bars are drawn on a 0–100% scale. Respondents could choose more than one view. Figures to verify against published data.

Guides

Start with one good question.

Browse all guides

Metaphysics · Beginner The Ship of Theseus: is it still the same ship? Replace every plank and ask what makes a thing itself. Your first puzzle about identity. Ethics · Beginner Stoicism and the things you can control What is up to us, what is not, and how to tell them apart. Logic · Beginner Valid, sound, true: three words people mix up How to judge an argument by its shape before its content. Epistemology · Beginner Can you be sure you are not dreaming? Radical doubt and the one thing it cannot touch. Political philosophy · Beginner The social contract in ten minutes Why anyone should obey a government at all. Aesthetics · Beginner Is beauty in the eye of the beholder? Taste, disagreement and whether some judgments are better. Epistemology · Intermediate Plato's cave, explained without the jargon Prisoners, shadows and the climb into daylight. Ethics · Intermediate The trolley problem and what it really tests Why switching feels fine and pushing does not. Metaphysics · Intermediate Free will: three positions and their costs Determinism, libertarianism and the compatibilist middle. Political philosophy · Intermediate Justice behind the veil of ignorance Choosing rules for a society without knowing your place in it. Logic · Intermediate Paradoxes worth losing sleep over The liar, the heap and what they show about language. Ethics · Advanced Reading Kant's Groundwork without giving up The categorical imperative, section by section.

What's coming

A library that grows
page by page.

Live Branch hubs, beginner guides and the first three tools
Next Thinker profiles, schools of thought and a full timeline
Later Eastern traditions, primary-text companions and course packs for teachers

Common questions

Frequently asked.

: No. There are no modules, no deadlines and no certificate. It is a reference and a set of tools — use it in the order that matches what you are curious about. If you want a structured introduction, the Ship of Theseus guide is a good first step.
: Every guide states its level: Beginner, Intermediate or Advanced. Start with Beginner guides and move up when you want more detail. The Philosophy Basics site is a useful companion if you want more introductory context.
: Yes. Every quote states the work and passage it comes from. We also note lines that are commonly misattributed. The Project Gutenberg library hosts many primary texts for free, and the Stanford Encyclopedia of Philosophy is the authoritative academic reference.
: Yes. The Argument Mapper, Fallacy Finder and Thought Experiment Lab all run in your browser. Nothing you type is sent anywhere. They use no cookies and no analytics.
: Project Gutenberg hosts thousands of philosophy texts whose copyright has expired. Perseus Digital Library offers Greek and Latin texts with translations. For contemporary philosophy, many authors post working papers on PhilArchive.
: There is no single correct order, but most people find it helpful to start with a branch that matches a live question they have — ethics if you face a moral dilemma, epistemology if you are thinking about what you can know. The Reading Path Builder tool (coming soon) will suggest an order based on your interests.
: We prioritise questions that are most searched, most debated and most relevant to everyday decisions. We also follow the PhilPapers Survey to see which positions professional philosophers actually hold, so we can represent live debates rather than outdated textbook summaries.

Think clearly about what matters.

Metaphysics

Pick the question thatbothers you most.

Philosophy youcan practise.

See the shape of the subject.

Start with one good question.

A library that growspage by page.

Frequently asked.

Think clearly about
what matters.

Pick the question that
bothers you most.

Philosophy you
can practise.

A library that grows
page by page.