Logic

Key people

• Bertrand RussellBritish philosopher and logician (1872–1970)
• Kurt GödelAustrian-American logician, mathematician, and philosopher of mathematics (1906–1978)
• Jean PiagetSwiss psychologist, biologist, logician, philosopher and academic (1896–1980)

Read

• The Logic of Scientific DiscoveryKarl Popper · 1935Book
• The Game of LogicLewis Carroll · 1886Book
• Introduction to logicIrving Marmer Copi · 1953Book
• Philosophical essaysBertrand Russell · 1910Book

Listen

• Logically SpeakingLogicPodcast
• Learning LogicMolly BPodcast
• The Art of Reasoning | Audiobook: A Practical Guide to Logic & ArgumentPedram KeshavarziPodcast
• Critical Reasoning: A Romp Through the Foothills of LogicOxford UniversityPodcast

Voices to follow

• Robert BrandomYouTubeAmerican philosopher
• David Kyle Johnson@kyle8425 · XAmerican university professor (born 1977)
• Sebastian Rudolph@sebrudolph · XGerman computer scientist and full professor
• Łukasz Kaiser@lukaszkaiser · XMachine learning researcher

Debates

• Is logic discovered or invented?One view: Logic reflects fundamental truths about reality, existing independently of human thought and waiting to be uncovered. · Another: Logic is a human construct, a system we create to organize and evaluate our reasoning, adaptable to different contexts.Open question
• Can all valid reasoning be formalized?One view: All genuinely valid reasoning can ultimately be expressed and evaluated through formal logical systems. · Another: Some forms of human reasoning, such as intuition or creative insight, resist complete formalization by logical systems.Open question

Glossary

• PremiseA statement assumed to be true that forms part of an argument.
• ConclusionThe statement an argument aims to prove, derived from its premises.
• ValidityAn argument is valid if its conclusion must be true whenever its premises are true.
• SoundnessAn argument is sound if it is valid and all its premises are actually true.
• DeductionReasoning from general principles to specific conclusions, guaranteeing the conclusion if premises are true.
• InductionReasoning from specific observations to general principles, providing probable but not guaranteed conclusions.

Careers

Roles this can lead toward

Threads 4

Where this connects to other fields — and why it's worth knowing.

• Cognitive Biases Psychology

  Give people a dry logic puzzle with letters and numbers and most flub it. Reword the exact same puzzle as 'catch the person cheating you,' and suddenly almost everyone nails it. That's a clue our brains didn't evolve for pure logic, they evolved to spot cheaters, and reasoning runs best on social fuel.

• Algorithms & Computation Mathematics

  'This sentence is false.' If it's true, it's false; if it's false, it's true. It looks like a silly word trick, but that same loop of a thing talking about itself is the exact trap that proves some problems no computer can ever solve, no matter how powerful. A brain-teaser and a hard limit on all computers turn out to be the same idea.

• Software Engineering Technology

  Proving a math theorem and writing a bug-free program turn out to be the very same act. A discovery called the Curry-Howard correspondence says a proof literally is a program, and the theorem it proves is that program's type. Logic and coding aren't cousins; they're the same thing wearing two outfits.

• Courts, Judges & Legal Reasoning Law

  In strict logic, once you've proven something, no new fact can ever undo it. But law has to allow exactly that, one fresh piece of evidence can flip a whole verdict. So courts secretly run on a bendable kind of logic where adding a single new fact is allowed to knock down the entire conclusion.