Presumption vs. Assumption: What’s the Difference?
Both “presumption” and “assumption” involve accepting something as true. But where they diverge is in why you accept it as true. One is based on evidence, while the other is based on, well, not so much. Understanding the difference between these two words is important for clear and effective communication.
This article digs into the definitions of “presume” and “assume,” highlighting their similarities and, more importantly, their differences. We’ll explore the etymology of each word and provide examples to illustrate the subtle distinctions that set them apart. By the end, you should have a solid grasp on when it’s appropriate to use one over the other, and you’ll be able to confidently explain the difference between presumption vs assumption.
We’ll start with the definitions, then move into the similarities and differences, and finally, we’ll wrap up with examples of how each word is used in context.
Defining “Assume”: Accepting Without Proof
When you assume something, you’re accepting it as true even though you don’t have proof or much evidence to back it up. The key thing about assuming is that you’re believing something without having solid support for that belief.
For instance, you might say, “I assume he’s coming to the party, but I haven’t actually spoken to him.” In this case, you’re thinking he’ll be there, but you haven’t confirmed it with him directly. Maybe he always comes to parties, so you’re just figuring he’ll be at this one too.
But assume can also mean to take on a responsibility or a role. If you’re taking on a task, you’re assuming responsibility. Like this: “She will assume the position of team leader next month.” In this example, assume means that she’s going to start being the team leader.
The word assumption is just the noun form of assume. It carries the same idea of not having enough evidence or proof. If you make an assumption, you’re basing your idea on something that isn’t necessarily a sure thing.
An example of this might be, “My assumption was that the meeting would be held in the conference room.” You thought it would be in the conference room, but you weren’t entirely sure. It could be somewhere else. You just assumed it was in the usual spot.
“Presume”: Accepting with Some Evidence
To “presume” something is to take it as true based on some evidence, probability, or likelihood. The key word is “some.” You’re not just pulling it out of thin air; there’s a little something backing you up, even if it’s not the whole story.
For example, you might say, “I presume she’s running late, since traffic is always bad at this hour.” There’s no guarantee she’s stuck in traffic, but the general likelihood during that time of day gives you a basis for your presumption.
The word “presume” can also mean to dare to do something, often with a hint of boldness or even audacity. It’s like you’re pushing the boundaries of what’s considered acceptable.
Think of saying, “I wouldn’t presume to offer advice to someone with so much experience.” In that case, you’re not necessarily thinking something is true, but more that you wouldn’t overstep your bounds.
Jane Austen also used the word in this sense when she wrote, “Not that I presume to insinuate, however, that some people may not think you perfection already” (Emma).
“Presumption” is simply the noun form of “presume,” and it carries the same sense of relying on partial evidence or probability. It’s a belief that’s based on something, but not everything.
A common example is, “The presumption of innocence is a cornerstone of our legal system.” The idea isn’t that everyone is innocent, but that they should be treated as such until proven guilty, even if there’s some evidence suggesting otherwise.
Key Differences Between “Assume” and “Presume”
Both “assume” and “presume” mean to suppose something is true, but there’s a subtle difference between the two. The main difference lies in how much evidence you have to back up your belief.
Level of Evidence
“Assume” implies that you’re making a guess with little or no evidence. “Presume,” on the other hand, suggests you have some evidence or a reasonable probability that something is true.
For example, if you’ve never met someone and you decide they’re angry, you’re assuming they’re angry based on no information. But if you’re talking to someone, and they speak in a loud voice and make fists, you might presume they’re angry based on their tone of voice and body language.
Contextual Nuances
The words “assume” and “presume” can subtly alter the meaning of a sentence. “Presume” can suggest a level of confidence or justification that “assume” doesn’t have.
If you say, “I assume you’re coming,” it’s a fairly neutral statement. But if you say, “I presume you’re coming,” it suggests you’re expecting them to come, maybe because you invited them or they told you they would be there.
Etymological Roots
Looking at the origins of the words can also help you understand the difference.
“Assume” comes from the Latin word “assumere,” which means “to take up.” “Presume” comes from the Latin “praesumere” and the Middle French “presumer,” meaning “to take beforehand.”
So, “assume” is a general taking-on of an idea, while “presume” is a taking-beforehand, based on something you already know or believe.
Practical examples and usage scenarios
While “assume” and “presume” may seem interchangeable, understanding their nuances can add precision to your language. Here are some everyday, formal, and literary examples.
Everyday scenarios
Think about this: You walk into your child’s room and it’s a mess. You might assume they haven’t cleaned it up. On the other hand, if they usually clean it on Saturdays and today is Saturday, you might presume they’ve already done it.
Another example: You’re heading to a store. You might assume it’s open. But if you checked their website and saw they’re open until 9 PM and it’s only 7 PM, you might presume it’s open.
Formal scenarios
In a courtroom, a jury presumes the defendant is innocent until proven guilty. This is a legal principle. Now, imagine you’re starting a new project at work. You might assume responsibility for it, meaning you’re taking it on. However, you wouldn’t presume to have the authority to make sweeping changes without consulting your boss first.
Literary examples
Shakespeare, in Hamlet, uses “assume” when Hamlet talks about the ghost: “If it assume my noble father’s person…” Here, “assume” means to take on a form or role.
Dickens, in Great Expectations, uses “assume” to mean adopting a dress more like a prosperous farmer’s.
And in a quote from the article that inspired this piece, “presume” can mean acting without authorization, to dare to steal.
Frequently Asked Questions
What are some examples of presumption?
A common example of presumption is “presumption of innocence” in law, where a person is considered innocent until proven guilty. Another example is presuming someone is home because their car is in the driveway. It’s essentially taking something as true without concrete proof, based on what seems most likely.
What is the difference between “presume” and “assume”?
While similar, “presume” often implies a slightly stronger basis than “assume.” Presuming usually involves some evidence or past experience, while assuming can be based on little or no evidence at all. You might presume a restaurant is good based on reviews, but assume it’s open based on its normal business hours.
Is “presumptuous” the same as “assuming”?
No, “presumptuous” is an adjective that describes behavior, not a state of mind. To be presumptuous is to be overbearing, arrogant, or to take liberties without permission. It’s about acting in a way that implies you have a right to something you don’t, often based on an incorrect assumption.
What is the difference between “presumptive” and “assume”?
“Presumptive” is an adjective describing something that is likely but not certain. For example, a “presumptive diagnosis” is based on initial findings but requires further confirmation. “Assume,” on the other hand, is a verb meaning to take something for granted without proof. So, you might assume someone has a cold based on their sniffles, leading to a presumptive diagnosis, pending a test.
In Summary
“Assume” and “presume” are similar, but they’re not interchangeable. When you assume something, you’re taking it for granted without having much proof. When you presume something, you’re basing your belief on some facts or a reasonable probability.
Choosing the right word comes down to whether you have evidence and what the context is. Using “presume” when you mean “assume” — or the other way around — can weaken your argument and confuse your audience.
When you use language carefully, you’re more likely to be understood. Paying attention to the nuances of words like “assume” and “presume” will make your writing and speaking clearer and more credible. Even better, careful word choices can help avoid misunderstandings and build stronger relationships with the people you’re trying to reach.