logic

noun

log·​ic ˈlä-jik How to pronounce logic (audio)
1
a(1)
: a science that deals with the principles and criteria of validity of inference and demonstration : the science of the formal principles of reasoning
a professor of logic
(2)
: a branch or variety of logic
modal logic
Boolean logic
(3)
: a branch of semiotics
especially : syntactics
(4)
: the formal principles of a branch of knowledge
the logic of grammar
b(1)
: a particular mode of reasoning viewed as valid or faulty
She spent a long time explaining the situation, but he failed to see her logic.
(2)
: relevance, propriety
could not understand the logic of such an action
c
: interrelation or sequence of facts or events when seen as inevitable or predictable
By the logic of events, anarchy leads to dictatorship.
d
: the arrangement of circuit elements (as in a computer) needed for computation
also : the circuits themselves
2
: something that forces a decision apart from or in opposition to reason
the logic of war
logician noun

Did you know?

How are logistics and logic related?

Logistics follows the same pattern of other plural nouns—such as ballistics, linguistics, statistics, or physics—that represent fields of study and take either a singular or plural verb.

Logic, used strictly in the singular, is a science that deals with the formal principles of reason. If a visitor walks in the house with a wet umbrella, it is logical for one to assume that it is raining outside. Logistics, which involves such concerns as the delivery of personnel or supplies in an efficient manner, can often employ logic, such as by reasoning out the path least likely to interrupt the flow of a delivery:

As with many other areas of the economy, the digital revolution is having a profound effect on delivery logistics. The combination of mobile computing, analytics, and cloud services, all of which are fueled by the Internet of Things (IoT), is changing how delivery and fulfillment companies are conducting their operations.
—Andrew Meola, Business Insider, 14 Oct. 2016

Both logic and logistics ultimately derive from the Greek logos, meaning "reason." But while logic derives directly from Greek, logistics took a longer route, first passing into French as logistique, meaning "art of calculating," and then into English from there.

Examples of logic in a Sentence

If you just use a little logic, you'll see I'm right. There's no logic in your reasoning. There's some logic to what he says. There's a certain logic in what he says. The revolution proceeded according to its own logic. the logic of the situation
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
After the dust settled, DeChambeau had the opportunity to return to the subject, explaining that both McIlroy's attitude and his own words were in keeping with the logic of the moment. Nicholas Creel, MSNBC Newsweek, 18 Apr. 2025 Drug Discovery Quantum computers are especially good at simulating the real world because the real world follows the rules of quantum physics — something traditional computers, which rely on simple binary logic, struggle to replicate accurately. Bernard Marr, Forbes.com, 16 Apr. 2025 In particular, Taiwan dominates advanced logic chip production at 92% of all fabrication capacity according to the International Trade Administration, with South Korea making 8%. Elaine Kurtenbach, Chicago Tribune, 15 Apr. 2025 OpenAI’s definition, for instance, is rooted in cold business logic: a technology that can perform most economically valuable tasks better than humans can. Billy Perrigo, Time, 15 Apr. 2025 See All Example Sentences for logic

Word History

Etymology

Middle English logik, from Anglo-French, from Latin logica, from Greek logikē, from feminine of logikos of reason, from logos reason — more at legend

First Known Use

12th century, in the meaning defined at sense 1a(1)

Time Traveler
The first known use of logic was in the 12th century

Browse Nearby Words

Cite this Entry

“Logic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/logic. Accessed 26 Apr. 2025.

Kids Definition

logic

noun
log·​ic ˈläj-ik How to pronounce logic (audio)
1
: the study of the rules and tests of sound reasoning
2
: reasoning sense 1
especially : sound reasoning
no logic in that remark
3
: connection (as of facts or events) in a way that seems reasonable
the logic of a situation
4
: the arrangement of circuit elements (as in a computer) needed for computation

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