argument

a set of claims where some of them (the premises) are intended to support another claim (the conclusion).

argument diagram

also called argument map or argument tree, the diagram shows each of the premises and the conclusion of an argument represented by node. The diagram shows that the premises are supporting the conclusion through the direction of the arrows linking the nodes, which mirrors the support-direction from premises to conclusion in the argument. The diagram also shows whether each premise supports the conclusion independently or dependently.

conclusion

The sentence in an argument of which the speaker wants to persuade their audience.

conditional probability

The conditional probability given the premises is the probability of the conclusion given the truth of the premises.

counterexample

a situation in which while the premises are true the conclusion is nevertheless false. The existence of a counterexample makes a deductive argument invalid.

declarative sentence

a sentence that makes an assertion, namely, a claim that can be true or false.

deductive argument

the claim being made in this type of argument is that ifyou accept the premises are true, then you must, as a matter of logical necessity, accept the conclusion. There is no room for mere probability.

defeater

Additional evidence that would change our assessment if added to the premises, defeating our reasons for accepting the conclusion of the argument.

dependent support

this is provided by a premise when it is not enough by itself to effectively support the conclusion but depends on the presence of other premises to do so.

explanation

here the author putting it forward assumes the claim is already accepted by the audience and aims at clarifying why it is so through other claims.

extended argument

a larger argument in which the conclusion of a smaller argument (intermediate conclusion), which is a part of the larger argument, is used as a premise.

extraneous material

background, rhetoric, or digressions, present in the discourse but that don't add content to the argument and so should be omitted in the standard form reconstruction.

implicit material

material out that is part of the content of the argument but that is left out by the speaker because they believe the context of the discourse makes obvious what this material is and so they do not need towaste their time stating it explicitly. We should aim to locate the missing material and make it explicit in our standard form reconstruction.

independent support

this is provided by a premise when it is enough by itself to effectively support the conclusion without requiring the presence of other premises to do so.

indexical

a context-sensitive term (I, you, here, now...) whose reference shifts with speaker/time/place or other features of the context in which it is communicated.

indicator words

a series of words that usually signal that the argument (conclusion indicator) or a premise (premise indicator) is about to appear in the piece of discourse. inductive argument The claim being made in this type of argument is that if you accept the premises are true, then you should, as a matter of what is more probable than not, accept the conclusion. Logical guarantee is not required here.

inductive force

An argument is inductively forceful when (i) it is not deductively valid, and (ii) assuming the premises are true—and treating them as the only relevant information—it's more reasonable than not that the conclusion is true.

inductive inference

An argument is an inductive inference if (i) it is not deductively valid; (ii) its premises include information about a sample of a given population; and (iii) its conclusion extrapolates the information in the premises to all or part of the total population from which the sample is drawn.

inductive soundness

An argument is inductively sound (or cogent) if (i) it is inductively forceful, and (ii) all of its premises are actually true.

inference

any step from premises to conclusion within an argument.

intermediate conclusion

within an extended argument, the premise of the larger argument which is also a conclusion for a smaller argument contained therein.

premise

A sentence in an argument that is offered in support of the conclusion.

principal conclusion

also called main conclusion, within an extended argument, the conclusion of the larger argument under consideration. It is the last claim in the chain of argumentation.

principle of charity

when reconstructing arguments we should add only what the text plausibly supports, but also aim at the strongest and clearest version of the argument consistent with the context.

proposition

the factual content expressed by a sentence that makes an assertion (i.e., a sentence that can be true or false) on a particular occasion.

rational expectation

The degree to which a rational person would be entitled to believe something, given a specific set of available information (the evidence). We identify the probability of a proposition with its degree of rational expectation.

rational persuasiveness

An argument is rationally persuasive for a person (at a time) if: (i) the argument is either deductively valid or inductively forceful, (ii) it is reasonable for the person (at that time) to believe the premises, and (iii) it is not an inductively forceful argument that is defeated for that person (at that time).

representative sample

A sample is representative if it is similar to the whole total population it is drawn from.

rhetoric

any spoken or written attempt to get someone to believe, desire, or do something without attempting to give reasons for that belief, desire, or action—instead relying on other levers (fear, pride, belonging, vibes, imagery, catchphrases).

soundness

An argument is (deductively) sound if it is deductively valid and all its premises are true.

standard form

a device that lists all and only the supporting claims ( premises), draws an inference bar, and places the conclusion beneath it. This layout makes evaluation and comparison of arguments straightforward.

truth

a claim is true if what it asserts is how things actually are.

validity

An argument is (deductively) valid if it is impossible for all of its premises to be true and its conclusion to be false.

Inference to the Best Explanation

(IBE) or abductive reasoning. Some inductive arguments aim not merely to predict outcomes but to explain why observed facts occur; an IBE evaluates competing hypotheses and concludes that the explanation which best accounts for the observed data is probably true.

Theoretical virtues

Good explanations are assessed using several criteria, including power, depth, explanatory range, falsifiability, modesty, simplicity, and conservativeness, though these virtues can conflict and require judgment to balance. Explanations are context-sensitive: what counts as the “best” explanation depends partly on the audience, standards of rigor, and other practical constraints.

Arguments from analogy

infer that because two things are similar in certain respects, they are likely similar in another respect; such arguments are inductive and defeasible. Analogical arguments are stronger when the cited similarities are relevant to the conclusion and specific enough to distinguish the compared objects from others. Arguments from analogy often function as incomplete or implicit IBEs, relying on shared properties such that some of these either explain the conclusion or are explained by it.

Weak analogies

rely on superficial or irrelevant similarities, while strong analogies either lack relevant disanalogies or can show that apparent disanalogies are not relevant.

Causal reasoning

is closely connected to explanation and prediction and typically relies on causal generalizations, which can be expressed as generalized conditionals. Understanding necessary and sufficient conditions is essential for evaluating causal claims, especially since many real-world causes are probabilistic or contributory rather than strictly sufficient or Necessary.

Formal fallacies

are structural (invalidate the inference)

Affirming the consequent

If a conditional sentence is true, and the consequent (then-clause) is also true (affirming the consequent), that won't guarantee the antecedent (if-clause) is also true. The antecedent is a sufficient condition for the consequent, but the consequent can be true for other reasons (it is not a necessary condition), so this kind of reasoning is a fallacy.

Denying the antecedent

If a conditional sentence is true, and the antecedent (if-clause) is false (denying the antecedent), that won't guarantee the consequent (then-clause) is also false. The antecedent is a sufficient condition for the consequent, but the consequent can be true for other reasons (it is not a necessary condition), so the falsity of the antecedent doesn't guarantee the falsity of the consequent, and so this kind of reasoning is a fallacy.

Deriving “ought” from “is”

You cannot reach a prescriptive conclusion from purely descriptive premises without a normative bridge premise.

Informal/substantive fallacies

hinge on a false or unsupported general premise, so arguments may be valid/forceful yet unsound. Good practice: Make implicit premises explicit and apply the principle of charity before diagnosing a fallacy.

Majority rules cluster

Common practice (everyone does it so it is acceptable) and majority belief (most believe it s0 it is true) confuse popularity with justification/truth; “appeal to popularity” often functions as a rhetorical ploy rather than an argument.

Personal attacks

Ad hominem, ad hominem circumstantial, and tu quoque attack the speaker instead of the reasons. Character can affect credibility, but it does not settle truth—evaluate the reasons.

Morality vs. legality

Legal 6= moral and illegal 6= immoral; conflating the two is a fallacy.

Perfectionist fallacy

Rejecting a policy because it is not a complete solution ignores that partial improvements can be justified.

Appeal to authority

Cites the wrong kind of authority or one without relevant expertise/evidence; legitimate only when the authority is relevant and well-informed.

Appeal to ignorance

“Not disproved so true” or “not proved so false” is bad reasoning; only careful, exhaustive searches plus auxiliary facts can license such inferences.

Faulty argument techniques

Unlike fallacies, they are not always invalid or unsound; they rely on distraction, exaggeration, or omission rather than false general premises. They may persuade rhetorically but fail as rational arguments.

Red herring

Introduces an irrelevant premise that distracts from the issue at hand.

Slippery slope

Claims that one event will inevitably trigger a chain of undesirable consequences without sufficient evidence. Legitimate only when causal links are well supported (often overlaps rhetorically with appeal to fear).

Straw target

Misrepresents or oversimplifies an opponent's position to make it easier to refute. Violates the principle of charity by attacking a weaker, distorted version of the real argument.

False dilemma

Artificially restricts options (often to two) when more exist. Creates the illusion of a forced choice between extremes (“either/ or" framing).

Begging the question

Assumes the truth of its conclusion within its premises (circular reasoning). Can be valid or even sound but fails to rationally persuade anyone who doesn't already accept the conclusion.

Rhetorical ploys

(non-argumentative) Attempts to persuade without offering reasons; the persuasive force stems from manipulating feelings/psychology rather than providing support. Contrast with fallacies/ faulty techniques, which are argumentative but give bad reasons.

Appeal to novelty

“New so better.” Trades on fear of being outdated or vanity about being forward-looking; provides no comparative reasons.

Appeal to popularity

“Everyone is doing/buying it.” Non-argumentative version of majority belief/common practice; if reconstructed as an argument, it commits those fallacies.

Appeal to FOMO

Manufactured urgency/scarcity plus social proof to provoke anxiety about missing out; no reasons for value or quality.

Appeal to compassion/pity/guilt

Evokes sympathy or guilt to move us to act; can be a gateway to good reasoning if followed by clear evidence of effectiveness, but feelings alone are insufficient.

Appeal to cuteness

Associates claims/products with children/animals/ mascots to make them seem attractive or memorable without reasons.

Appeal to sexiness

Associates a product/behavior with sexual attractiveness; also sells an aspirational self-image (“be like them”) rather than reasons.

Appeal to wealth/status/power/hipness/coolness

Prestige or trendiness by association substitutes for argument.

Appeal to identity (in-group similarity)

“People like us do/believe this.” Exploits in-group psychology and identification without evidence.

Appeal to fear

Scare tactics to force acceptance or action; distinguish from genuine warnings, which provide warranted links between risk and response.

Appeal to ridicule

Derision or mockery to discredit a view instead of engaging its reasons.

Direct attack / hard sell

Bare imperatives/slogans; repetition (“the hard sell”) replaces support.

Scare quotes

Use of quotation marks to insinuate suspicion or absurdity about key terms; contrast with legitimate quoting.

Many questions (loaded/complex)

Smuggles presuppositions by asking for an explanation of something not established.

Smokescreen (incl. whataboutism, tone policing)

Topic-shift or distraction to avoid the issue; whataboutism and focusing on tone rather than content are common forms.

Virtue signaling

Public display of moral stance to create social pressure rather than offer reasons; distinguish from genuine activism by cost/commitment, follow-through, and evidential backing.

Buzzwords, jargon, acronyms

Obscure meaning, create in-group vibes, or inflate credibility; note the difference between manipulative usage and legitimately precise technical language.

Spin

Strategic framing and messaging (often in politics/media) that packages facts to steer attitudes without argument.

Gas-lighting

Manipulates someone into doubting their memory/perception/ sanity, thereby undermining their claims without reasons.