Logical Fallacies

LogFall

A practical logical-fallacies reference with clear explanations, usable examples, and teaching tools.

Fallacy profile

All or nothing fallacy

Occurs when support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package.

EpistemicEvidential

Definition

Occurs when support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package.

Illustrative example

One error in this report means the entire investigation is worthless.

Teaching gauges

These 0-100 gauges are teaching aids for comparing fallacies. They are editorial classroom estimates, not measured statistics.

Recurring

65

Common in today's rhetoric

Common enough that most readers will meet it often.

Hard to spot

35

Easy to spot

Hard to see without slowing down and reconstructing the reasoning.

Very easy to slip into

75

Easy to innocently commit

A frequent unintentional slip in ordinary reasoning.

Intermediate

55

Difficulty

Needs some practice with categories, evidence, or debate structure.

High schoolScientific reasoning

Reference

Family

Conceptual/Framing Fallacy

The claim is distorted by bad categories, rigid framing, or confused conceptual boundaries.

Quick check

Is the speaker calibrating confidence to the strength of the evidence?

Why it misleads

A fuller explanation of how the fallacy works and why it can look persuasive.

Many systems of belief, institutions, and documents are mixed. Partial support or partial failure rarely justifies an everything-or-nothing verdict.

That's like saying...

Instead of leading with the label, this analogy answers the shape of the reasoning move directly so the mistake is easier to see in plain language.

Fallacious claim

One error in this report means the entire investigation is worthless.

That's like saying...

That's like throwing away the whole meal because one dish was oversalted. A flaw in part of the package is being treated as total failure of the whole.

Caveat

This label is easy to overuse. The point here is not to call every weak argument by this name, but to reserve it for the exact misstep it describes.

Common misapplication

Do not use this label every time someone sounds too confident, too skeptical, or too simplified. It applies when belief or doubt is being managed badly relative to what can responsibly be known.

Use the label only when...

Use this label only when support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package. If the real problem is that the wording of a negative position is manipulated so that mere non-belief is treated as if it were the same thing as a strong positive denial, the better label is Artificial negation.

Often confused with

These near neighbors are easy to mix up, so use the comparison to see the exact difference.

Comparison

Artificial negation

Why people mix them up: Both often look like epistemic and evidential mistakes at first glance.

Exact difference: All or nothing fallacy happens when support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package. Artificial negation happens when the wording of a negative position is manipulated so that mere non-belief is treated as if it were the same thing as a strong positive denial.

Quick split: Is the speaker calibrating confidence to the strength of the evidence? Then compare it with Is the speaker calibrating confidence to the strength of the evidence?

Comparison

Argument from incredulity

Why people mix them up: Both often look like epistemic and evidential mistakes at first glance.

Exact difference: All or nothing fallacy happens when support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package. Argument from incredulity happens when someone treats their inability to imagine, explain, or believe a claim as evidence that the claim must be false, or conversely true.

Quick split: Is the speaker calibrating confidence to the strength of the evidence? Then compare it with Is the speaker calibrating confidence to the strength of the evidence?

Practice And Repair

Extra teaching tools that show why the fallacy is persuasive, what to look for, and how to correct it.

Why it matters

Why this mistake matters

All or nothing fallacy threatens rationality because support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package.

Main reasoning problem

Support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package.

Why this kind of mistake matters

It corrupts the calibration of belief, doubt, burden, uncertainty, or standards of evidence.

Check yourself

The assessment area now uses mixed 10-question sets, so the fallacy is not announced in the title before the quiz begins.

What the assessment does

You will work through a mixed set of fallacy-identification questions. Focused links from a fallacy page will quietly include this fallacy among nearby look-alikes without announcing the answer in the page title.

Questions to ask

Use these category-based prompts to audit similar arguments.

Prompt 1

Is the speaker calibrating confidence to the strength of the evidence?

Prompt 2

What evidence is missing, selected, or overstretched here?

Case studies

Each case study explains why the example fits the fallacy and links back to its source whenever source information is available.

In 2024 media battles, a single correction or mistaken detail was often used to dismiss an outlet's entire reporting on elections, immigration, or public health. The fallacy here is All or nothing fallacy: support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package. That matters here because many systems of belief, institutions, and documents are mixed. A better analysis would remember that partial support or partial failure rarely justifies an everything-or-nothing verdict.

Religious, ideological, and policy debates often act as though rejecting one doctrine, statistic, or mechanism commits you to rejecting the entire worldview. The fallacy here is All or nothing fallacy: support for part of a view, or problems with part of a view, are treated as if they force total acceptance or total rejection of the whole package. That matters here because many systems of belief, institutions, and documents are mixed. A better analysis would remember that partial support or partial failure rarely justifies an everything-or-nothing verdict.

Related fallacies

Nearby entries chosen by shared categories and family resemblance.