What's taken for granted but never stated?
"We should ban phones in class because they distract students." HIDDEN ASSUMPTION: that banning will actually stop distraction! Arguments often rely on unstated beliefs. Finding these hidden assumptions is like detective work!
ASSUMPTIONS = unstated beliefs that an argument DEPENDS ON but doesn't SAY.
They're the invisible bridges between premises and conclusion.
Example: "Study hard to get good grades" ASSUMES grades reflect learning, studying helps, you have time to study, etc!
Ask these questions:
• What must be TRUE for this conclusion to follow?
• What's NOT being said?
• What if [assumption] is false? Does argument collapse?
• Fill the gap: "This works ONLY IF ______"
"Exercise more to lose weight!"
ASSUMES: weight loss is good, exercise causes it, you have time/ability, no medical issues, calories stay same
"Vote for me - I'm a successful businessman!"
ASSUMES: business skills = governing skills, success was ethical, past predicts future
Challenging assumptions reveals argument weaknesses!
If an assumption is FALSE, the whole argument can crumble - even if logic seems good!
Example: "Reading glasses help people see" ASSUMES you have eyes!
Critical thinkers examine assumptions, not just conclusions.
Hidden assumptions are unstated beliefs that arguments depend on but never explicitly say!
Why they're "hidden":
• So obvious we don't notice them
• Deliberately left out to avoid challenge
• Cultural - "everyone knows"
• Too many to state explicitly
How to expose them:
1. Look for GAPS between premise and conclusion
2. Ask: "For this to work, what else must be true?"
3. Try: "This fails if ______"
4. Question EVERY step, especially "obvious" ones
Example breakdown:
Argument: "Schools should start later so teens get more sleep"
Hidden assumptions:
• Later start → actually sleep more (not just stay up later!)
• More sleep → better outcomes
• No other solutions exist
• Schedule change is feasible
• Benefits outweigh costs
Power of assumption-hunting: Once you see the unstated beliefs, you can challenge them! Many "obvious" arguments collapse when assumptions are questioned!
🤔 Which thinking lens(es) did you use?
Select all the lenses you used:
🌱 A Small Everyday Story
"Just study more and you'll do better!"
"What does that assume?"
"Um... that I have time? That studying helps?"
"What else?"
"That I know HOW to study... that the test is fair..."
"So many hidden beliefs in one simple statement!"
See more guidance →
🧠 Thinking habits this builds:
- Looking for what's NOT said
- Questioning "obvious" beliefs
- Finding gaps in arguments
- Testing whether assumptions hold
🌿 Behaviors you may notice (and reinforce):
- Asking "What does that assume?"
- Noticing unstated beliefs in advice
- Challenging "everyone knows" statements
- Filling in the gaps: "This only works if..."
How to reinforce: "You found a hidden assumption that the argument depends on! Now we can check if that assumption is actually true."
🔄 When ideas are still forming:
Children might think assumptions are lies. Help them see assumptions are often reasonable - but should still be checked.
Helpful response: "Assumptions aren't bad - we can't say everything! But knowing they're there lets us check if they're true."
🔬 If you want to go deeper:
- Find 5 assumptions in one piece of advice
- Why do some assumptions remain hidden?
- When should we challenge assumptions?
Key concepts (for adults): Hidden assumptions, implicit premises, presuppositions, unstated beliefs.