Used and loved by millions
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com
by what rationale
Grammar usage guide and real-world examplesUSAGE SUMMARY
"by what rationale" is correct and usable in written English.
This phrase is used to ask someone to provide an explanation for why something is done or believed. For example: "By what rationale do some people consider this food to be unhealthy?".
✓ Grammatically correct
News & Media
Alternative expressions(20)
what's the justification
what is the basis
on what grounds
what is the explanation
what is the thinking behind
what led to this
what are the reasons
why was this done
on what platform
on what based
on what purpose
by what principles
on what reason
on what foundation
on what base
on what evidence
what is the foundation
by what criterion
upon what authority
on what standard
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Human-verified examples from authoritative sources
Exact Expressions
2 human-written examples
By what rationale have manufacturers offered these weapons for sale to the public?
News & Media
By what rationale do we insist that groups — races, communities of faith — don't deserve similar protection?
News & Media
Human-verified similar examples from authoritative sources
Similar Expressions
57 human-written examples
What rationale did terrorist groups give for their actions?
News & Media
By what insane rationale does dismissing gay and lesbian military personnel who can actually speak the language of the occupied make the servicemen and women serving there safer?
News & Media
Again, we don't know the rationale, but what other rationale could there be?..
News & Media
Again, we don't know the rationale, but what other rationale could there be?" Santorum said.
News & Media
Although the rationale has survived, and is still trotted out by those who support today's cuts, it has been eclipsed, at least partly, by what you might call the moral case against taxation.
News & Media
Let's applaud corporate generosity, no matter what the rationale.
News & Media
Nor was it clear what the rationale was behind it.
News & Media
What possible rationale did John McCain have for selecting Sarah Palin?
News & Media
They need to know what the rationales are".
News & Media
Expert writing Tips
Best practice
Use "by what rationale" when you want to formally question or challenge the reasoning behind a decision, action, or belief. It's particularly effective in academic, journalistic, or professional contexts where a clear explanation is expected.
Common error
Avoid using "by what rationale" when you actually mean to critique a "rationalization". "Rationale" seeks the real reasons behind something, while "rationalization" implies creating self-justifying explanations, often after the fact. Using the former when you mean the latter can weaken your critique.
Source & Trust
89%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "by what rationale" functions as an interrogative adverbial phrase. According to Ludwig AI, it serves to question or request the underlying reasons or justifications for a particular action, decision, or belief. It sets the stage for a demand of reasoning.
Frequent in
News & Media
100%
Science
0%
Formal & Business
0%
Less common in
Science
0%
Formal & Business
0%
Encyclopedias
0%
Ludwig's WRAP-UP
In summary, "by what rationale" is a grammatically sound phrase used to formally question the basis of a decision or belief. As noted by Ludwig AI, its purpose is to elicit a clear and justified explanation. Given its appearance in news and media, and given the nature of the related phrases such as "on what grounds", it serves to invoke critical thinking, making it a useful tool for requesting accountability and transparency. This phrase should be used when a well-reasoned explanation is expected and one desires to scrutinize the underlying logic.
More alternative expressions(10)
Phrases that express similar concepts, ordered by semantic similarity:
on what grounds
This alternative focuses on the basis or justification used to support a claim or action.
what's the justification
This alternative asks directly for the reason that defends or justifies something.
what is the basis
This alternative seeks the underlying principle or foundation upon which something is based.
by what reasoning
This alternative emphasizes the logical process used to arrive at a conclusion.
what is the explanation
This alternative seeks a detailed account that clarifies the reasons behind something.
what is the thinking behind
This alternative explores the thought process and considerations that led to a decision.
what led to this
This alternative inquires about the events or factors that preceded and influenced a particular outcome.
what's the logic
This alternative seeks the underlying logical principles or structure.
what are the reasons
This alternative is a direct request for the causes or justifications for something.
why was this done
This alternative is a simple and direct inquiry into the reasons for a specific action.
FAQs
How can I use "by what rationale" in a sentence?
The phrase "by what rationale" is used to inquire about or challenge the reasons behind a decision, action, or belief. For example, "By what rationale were these budget cuts implemented?" or "By what rationale do you defend this policy?". It invites a formal explanation.
What are some alternatives to "by what rationale"?
You can use alternatives such as "on what grounds", "what's the justification", or "what is the basis" depending on the context. These alternatives also seek the reasoning or justification behind something.
Is "rationale" the same as "reason"?
"Rationale" is a more formal and comprehensive term than "reason". While "reason" can refer to a single cause or explanation, "rationale" implies a coherent set of reasons or principles that justify a particular course of action or belief. Therefore, asking "by what rationale" suggests a deeper inquiry than simply asking "what is the reason".
When is it appropriate to use "by what rationale"?
It's appropriate to use "by what rationale" in situations where you're seeking a formal, well-reasoned explanation for a decision or action. This phrase is often used in academic, professional, or journalistic contexts where critical analysis and justification are important.
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Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
89%
Authority and reliability
4.5/5
Expert rating
Real-world application tested