assumption
B2Pronunciation
UK
- /əsˈʌmpʃən/
US
- /əˈsəmpʃən/
Description
- belief
- guess
- presumption
An assumption is something you think is true without proof – a kind of educated (or not-so-educated!) guess. It's like building with blocks before checking if the foundation is solid. You might make an assumption about someone's intentions, or assume a store will be open based on its usual hours. But remember the old saying: to assume makes an "ass" out of "u" and "me"! Assumptions can lead to misunderstandings if they aren't checked against reality. Think of Sherlock Holmes – he avoids assumptions and relies on evidence instead.
An assumption is an idea accepted as true or certain to happen, often without proof. It's the mental leap we take when we fill in gaps in our knowledge, usually unconsciously. We make assumptions constantly throughout the day, from simple things like assuming your coffee will be hot, to more complex ones about people's motivations. (Note: In very formal contexts, the word can also mean "taking on" responsibility—like the "assumption of command"—but we mostly use it to talk about beliefs).
The context is important. In everyday conversation, it simply means a belief held without concrete evidence. "I made the assumption that because she was smiling, she was happy." However, in fields like logic, statistics, and law, assumptions are carefully defined starting points for reasoning. A faulty assumption can derail an argument or lead to incorrect conclusions.
Sometimes, assumptions are harmless shortcuts that help us navigate daily life. Other times, they can be dangerous—leading to prejudice, miscommunication, or poor decision-making. A detective might challenge every assumption in a case, while a storyteller might build a narrative around an unstated assumption about human nature.
Consider the phrase "Don't jump to conclusions." It's essentially a warning against making assumptions without gathering enough information. So, while assumptions are inevitable, being aware of them—and willing to question them—is crucial for clear thinking and effective communication.
Examples
- 1
Project planning
We made a few assumptions before we started the project.
- 2
Travel expectation
Her decision was based on the assumption that the train would be on time.
- 3
Personal motives
I don't want to make assumptions about his reasons.
- 4
Reasonable guess
That was a fair assumption, given the information you had.
- 5
Emergency situation
He worked under the assumption that someone else had already called the police.
Pattern
under the assumption that + clause
believing that something is true
- 6
Policy report
The report challenges the assumption that bigger classes always save money.
- 7
Social customs
Many social customs depend on shared assumptions about polite behavior.
- 8
Business planning
Their business plan rests on the assumption of steady growth.
Phrase
rests on
depends on
Forms and spellings
2 forms open this card.
Main spelling
- assumptionnoun
Forms
- assumptionspluralnoun