Knew.si
How do we know what we know? A critical thinking guide
Knew.ai teaches epistemology and critical thinking in practice - how claims get verified, how to evaluate sources, spot logical fallacies, and separate evidence from assumption. Built for students, researchers, and anyone who wants to think more clearly.
No card required · $9/mo Plus · $99/mo Premium
What you get
Everything Knew.si gives you
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Source evaluation
A practical method for judging whether a source is reliable.
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Fallacy spotting
Name and recognize common reasoning errors in arguments.
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Evidence vs assumption
Learn to separate what's demonstrated from what's merely believed.
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Saved study threads
Sign in free and keep every conversation for later study.
Go deeper
Thinking Clearly, Explained
Practical tools for evaluating claims and evidence.
Core Method
- Primary vs secondary sources — Firsthand evidence versus accounts that interpret it.
- Corroboration — Checking a claim against independent sources before trusting it.
- Falsifiability — Whether a claim could, in principle, be shown wrong by evidence.
Common Errors
- Confirmation bias — The tendency to favor evidence that confirms existing beliefs.
- Correlation vs causation — Two things moving together does not mean one causes the other.
- Appeal to authority — Treating a claim as true only because an authority said so.
Pricing
Simple plans that grow with you
Most popular
Plus
$9/mo
- ✓200 questions per day
- ✓Full saved conversation history
- ✓Guided claim-evaluation walkthroughs
Premium
$99/mo
- ✓Unlimited questions
- ✓Extended deep-dive answers
- ✓Everything in Plus