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 if

you 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 to

waste 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.

Some inductive arguments aim not merely to predict outcomes but to

explain why observed facts occur; this pattern of reasoning is known as

Inference to the Best Explanation (IBE) or abductive reasoning.

• An IBE evaluates competing hypotheses and concludes that the explanation

which best accounts for the observed data is probably true.

• 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.

• Weak analogies rely on superficial or irrelevant similarities, while

strong analogies either lack relevant disanalogies or can show that

apparent disanalogies are not relevant.

• 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.

• 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.

Two families of fallacies: Formal fallacies are structural (invalidate

the inference); informal/substantive fallacies hinge on a false or unsupported

general premise, so arguments may be valid/forceful yet unsound.

• Conditional missteps (formal): Affirming the consequent and denying

the antecedent mistake sufficient for necessary conditions.

• “Ought” from “is” (formal): You cannot reach a prescriptive conclusion

from purely descriptive premises without a normative bridge

premise.

• Majority rules cluster (informal): Common practice (everyone

does it ) it is acceptable) and majority belief (most believe it ) it is

true) confuse popularity with justification/truth; “appeal to popularity”

often functions as a rhetorical ploy rather than an argument.

• Personal attacks (informal): 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 (informal): Legal 6= moral and illegal 6= immoral;

conflating the two is a fallacy.

• Perfectionist fallacy (informal): Rejecting a policy because it is not

a complete solution ignores that partial improvements can be justified.

• Appeal to authority (informal): 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 (informal): “Not disproved ) true” or “not

proved)false” is bad reasoning; only careful, exhaustive searches plus

auxiliary facts can license such inferences.

• Good practice: Make implicit premises explicit and apply the principle

of charity before diagnosing a fallacy.

• 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)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.