Reasoning and self-knowledge (Philosophy HL)

The big idea: Reason is one of our sources of knowledge — but reasoning comes in two very different flavours, and mixing them up causes real mistakes.

One gives you certainty. The other only gives you a good bet — and a surprising amount of what we call knowledge rests on the second.

Checkpoint — deduction vs induction: In one line: deduction goes general → particular and is certain; induction goes cases → rule and is only probable. Science and everyday life lean heavily on the probable kind.

Induction feels rock-solid — until Hume asks one simple question about it.

Why should the future be like the past?: David Hume noticed that all inductive reasoning secretly assumes one thing: that the future will resemble the past. The sun rose every day so far, so we bet it will tomorrow — but that bet only works IF nature keeps behaving as it has. And how do we know it will? Only because it always has before — which is using induction to justify induction, going in a circle. This is the problem of induction.

Go further — higher-level insight: Hume isn't telling you to stop trusting the sunrise. His point is deeper: induction can't be given a logical PROOF, yet we can't live without it. So maybe knowledge of the world was never about certainty at all — it's about reasonable, well-supported bets. Framing induction as 'rational belief without proof' is a top-band move.

Checkpoint — the problem of induction: In one line: induction can't be proven, because any proof would itself have to use induction — yet we can't do without it.

One last question turns knowledge inward: is knowing your own mind surer than knowing the world?

The case for self-knowledge being special: There's an old thought that self-knowledge is the most certain knowledge of all. You might be wrong that it's raining, but surely you can't be wrong that you feel cold or seem to see red? Your own inner states are right there — no senses to fool you, no testimony to distrust. Descartes leaned on exactly this: even doubting everything else, you can't doubt your own thinking.

The pushback: you can be a stranger to yourself: But it's not that simple. People are often wrong about WHY they did something, deceive themselves about what they really want, and don't notice their own moods until a friend points them out. So while you may have special access to the feeling of a moment, real self-knowledge — understanding your own character and motives — can be as hard-won as knowledge of anything else.

Checkpoint — self-knowledge: In one line: you may be certain of how you FEEL, but understanding your own character and motives can be as hard as knowing the world.

How Section B works: Section B is an ESSAY [25] on an optional theme like epistemology — NO stimulus, just a question you argue. The command is usually 'Evaluate' or 'Discuss'. You pick views, argue them, weigh them, and reach a reasoned conclusion — this whole topic feeds it.

Common mistakes: 1. Describing views instead of arguing them. 2. Only one view — top bands need tension. 3. No conclusion — decide, with a reason. 4. Name-dropping — a name earns nothing without its argument. 5. Forgetting §B needs NO stimulus — just argue the question.