Ruggero J. Aldisert, Agatha D. Aldisert — Logic for Lawyers- A Guide to Clear Legal Thinking

227 published claims from this book.

• A belief is an accepted assertion lacking absolute proof but prompting action
• A capital offense in Florida is exclusively punishable by death
• A case is precedent only when material facts match exactly
• A case precedent only holds for the precise issue before it
• A categorical proposition is a statement about classes.
• A categorical syllogism contains two premises and a conclusion
• A categorical syllogism must contain exactly three terms used consistently
• A country’s culinary reputation does not guarantee any single restaurant matches it
• A disjunctive syllogism requires mutually exclusive and collectively exhaustive alternatives
• A distributed term refers to every member contained under that term.
• A fallacy is an argument that seems valid but fails logic
• A formal fallacy is an argument whose conclusion could be false.
• A good decision is measured by weighing of interests and durability, not result
• A holding’s rationale can become immaterial as judicial perspectives shift.
• A judicial precedent attaches specific legal consequences to detailed case facts.
• A legal principle emerges from a long line of decisions.
• A polysyllogism is a connected series of logical syllogisms.
• A single observed sequence may be arbitrary coincidence
• A sound deductive argument is valid and contains true premises
• A statute of limitations makes stale claims legally unenforceable after one year
• A syllogism is an argument containing premises and a conclusion.
• A universal proposition contains a distributed subject term while particular propositions are undistributed.
• A valid categorical syllogism requires its middle term distributed once
• A valid syllogism must involve exactly three distinct terms.
• Absence of evidence counts as evidence only when a competent, resourced search was conducted
• Advocates debate whether case factual similarities are legally material
• Affirmative propositions leave their predicate term undistributed
• Affirming the consequent fails because multiple independent conditions can produce it
• Amphibology causes ambiguity through grammatical structure rather than word meaning
• Amphibology infects the entire argument, while equivocation is confined to single terms
• An ad hominem attack shifts the focus from the argument to the arguer’s character
• An appeal to novelty is the mirror-image counter-fallacy
• An enthymeme is a formal argument with an unexpressed premise or conclusion.
• An illicit major fallacy distributes an undistributed major term conclusion
• An illicit minor fallacy distributes an undistributed minor premise term
• An informal fallacy fails because its premises are untrue or rules are violated
• An institution presumed innocent a priori will be acquitted regardless of evidence
• An isolated act of negligence does not destroy marital tranquillity
• An official’s marriage to a minority woman disproves alleged racial bias
• An unprincipled and unsound legal argument can never be right
• Analogical reasoning fails when negative factual resemblances outweigh positive resemblances
• Analogical reasoning infers additional properties from shared case similarities
• Appeal to tradition may be legitimate within constitutional law
• Appeals to inflammatory hypotheticals constitute the argumentum ad populum fallacy
• Appeals to pity are fallacies only when they are irrelevant to the decision type
• Appeals to pity are fallacious when the question is purely factual
• Appellate courts inconsistently apply procedural waiver rules to different parties
• Arguing a fetus lacks rights because it is not born is circular reasoning
• Begging the question assumes the truth of what it purports to prove.
• Begging the question is the most litigation-generating logical fault
• Behavioral schemas cannot disambiguate unrelated phenomena producing the same signature
• Case by case adjudication allows unfair rules to be modified.
• Categorical, hypothetical, and disjunctive propositions differ by how they present conditions
• Chronological sequence alone never proves causation
• Circumstantial evidence cannot support legal liability when resting entirely on speculation
• Circumstantial evidence must support a reasonable inference rather than mere speculation
• Citing sources rhetorically when they lack dispositive effect constitutes an appeal to authority
• Civil law systems trace their source of law to written codes.
• Colored persons possessed voting rights in several original states during founding
• Common law adjudication cycles induction and deduction into new rules
• Common law legitimacy derives from published judicial opinions and public reasoning.
• Common-law principles help judges determine if case differences are significant
• Conceptual puzzles about ‘the law’ and ‘legal obligation’ become acute when a court is confronted with a problem like this.
• Conclusory allegations may not justify EEOC intrusion into tenure review
• Congressional acts conflicting with the Constitution are void
• Connecting events solely through a shared location commits an undistributed middle fallacy
• Conspiracy as a crime differs from conspiracy as an evidentiary rule
• Constitutional regulations cannot achieve state goals by sweeping unnecessarily broadly.
• Context alters the meaning of identical phrases in a confession
• Converse accident is erroneously creating a general rule from insufficient data.
• Courts extend general rules without committing a fallacy when underlying conditions match.
• Courts have the essential duty to interpret conflicting laws and constitutions
• Courts must decide only the case before them, not hypothetical future cases
• Courts refuse constitutional questions based upon inadequate factual records
• Criminal property theft valuation requires accounting for value received by victims
• Criminal sodomy prohibitions have ancient roots in American legal history.
• Deductive legal analysis applies established characteristic propositions to new cases
• Deductive legal reasoning requires identifying the controlling major premise.
• Defamation claims require affirmative proof that recipients understood reports as defamatory
• Defendants may waive statutory appeal rights via plea agreements
• Deference to agencies must not abdicate judicial review over policy decisions
• Denying the antecedent assumes that if P implies Q, then non-P implies non-Q.
• Denying the antecedent fails because alternative conditions can produce the consequent
• Denying the antecedent is an invalid logical inference in formal reasoning
• Direct evidence proves a fact without requiring inference or presumption
• Directed verdicts require courts to decide if facts permit reasonable inferences
• Disjunctive fallacies occur through missing disjuncts or nonexclusivity of options.
• Distributed terms in a conclusion must be distributed in the premises
• Drug courier profiles describe behaviors frequently shown by completely innocent people
• Elevating a single case holding to a principle causes improper legal breadth.
• Enlightenment defines reason as systematic organization of data
• Equivocation is confusing a word’s several meanings within an argument
• Establishing disparate impact requires comparing affected groups rather than proving individual disadvantage
• Factual propositions cannot be sustained merely by citing negative evidence
• Fallacies in missing disjuncts stem from omitting alternative possibilities
• Federal court standing depends on membership in the constitutional political community
• Federal racial classifications must serve compelling interests and remain narrowly tailored
• Geographic separation does not prove noninfringing status under patent law
• Grammatical gender assignment is arbitrary yet skews feminine for abstractions
• Hearsay rule exceptions mark where the general rule does not apply
• Historical practice by the First Congress reveals constitutional meaning beyond pattern alone
• Hobbs Act commerce effect raises separate jurisdictional and substantive questions
• I believe I must endorse both these observations. A glance at the law reviews dishearteningly confirms that the universities produce an enormous amount of legal criticism—really commentary on…
• Inductive enumeration and legal analogy differ only in conclusion breadth
• Inductive generalization derives universal legal rules from repeated particular case outcomes
• Inductive legal conclusions serve as major premises in deductive legal arguments.
• Inductive legal generalization produces workable probabilities rather than absolute truths.
• Inductive reasoning allows the law to adapt to changing societal times.
• Inductive reasoning from varying factual scenarios forms premises for deductive reasoning
• Inductive reasoning yields probability while deduction yields certainty
• Inferring causation merely from temporal sequence is the post hoc fallacy.
• Inferring the contrapositive from a universal negative proposition is invalid
• Innkeeper liability applies only to goods put in public house charge
• Intellectual work must produce new knowledges rather than recirculate known conclusions
• Intervening tortious acts by third parties break legal liability chains
• Issues should be framed so that holdings resolve to yes or no.
• Joint purchase does not prove coercion or an illegal tie
• Judges rely on personal values when competing legal principles are evenly balanced
• Judging requires selecting relevant facts and evaluating relative values
• Judicial decisions are governed by beliefs about facts and rules
• Judicial decisions depend entirely on articulated reasons rather than fiat
• Judicial generalization and analogical reasoning constitute the process of induction
• Judicial power to issue mandatory injunctions prevents reckless property investment in zoning disputes
• Judicial review is the judiciary’s core duty and province
• Judicial rules should not be applied to dryly logical extremes
• Knowledge of logical canons enables the detection of misleading legal arguments
• Law lacks fixed major premises unlike math and science
• Laws criminalizing conduct shielded by fundamental rights are unconstitutional
• Legal analogy argues from particular facts to particular consequences based on similarities
• Legal analogy requires a theoretical basis rather than mere perception
• Legal analysts evaluate deductive reasoning by starting from the conclusion.
• Legal categories remain ambiguous to accommodate changing community values
• Legal classifications and rules evolve through ongoing application to cases
• Legal criticism improves when focused on specific premises and syllogisms.
• Legal critique often masks a disagreement over underlying value judgments.
• Legal duty requires specific characteristics present in all precedent cases
• Legal errors frequently stem from failing to enumerate all alternatives correctly
• Legal inductions represent probabilities rather than absolute truths.
• Legal major premises derive authority from constitutional text or statutes
• Legal outcomes depend on variable choices and value judgments rather than absolutes.
• Legal precepts evolve slowly as working hypotheses continually retested in courts
• Legal reasoning employs both deductive and inductive processes iteratively.
• Legal reasoning reduces to the judge drawing distinctions and the lawyer predicting them
• Legal reasoning requires mastery of deductive and inductive logic principles.
• Legal reasoning yields probability rather than absolute mathematical truths
• Legal rules resting only on past authority deserve condemnation when their rationale has lapsed
• Liability under a guest statute requires a high probability of substantial harm.
• Like-cases-decided-alike leaves open what makes a case like another
• Logic tests the validity of propositions after value judgments drive decisions
• Logical form and avoiding fallacies remain critical tools of persuasion
• Logical reasoning provides the foundation that prevents common law from becoming arbitrary fiat.
• Logicians and lawyers use fallacy to mean incorrect argument.
• Material fallacies emerge from examining term meanings rather than form
• Materiality of a new circumstance determines whether precedent extends to analogous facts.
• More confirming instances increase the probability of an inductive conclusion.
• Natural-kind categories license inferences but forbid membership change
• Ninety percent of general-court cases involve settled law or settled application
• No genuine knowledge can be derived from a state of ignorance
• Not all defendant admissions qualify as direct evidence of a crime
• Omitted major premises in arguments are classified as first order enthymemes.
• Overbroad statutes are tainted when prohibiting both protected and criminal conduct
• Pending separate lawsuits do not defeat the finality of a judgment in one action
• Permissible jury inferences require a logical probability connecting basic facts to ultimate facts
• Personal attacks on candidates are legally irrelevant to ballot measures
• Popular acceptance neither proves truth nor wisdom of a belief
• Post hoc and non sequitur fail via different missing connections
• Presumption of innocence is a legitimate appeal to ignorance enshrined in law
• Prior problems with a structure do not negate a later sudden event.
• Procedural compliance alone does not immunize a zoning decision from judicial review
• Proving a different point than the actual issue is the fallacy of irrelevance
• Provocation must be submitted to the jury as a basis for mitigating punitive damages.
• Public policy requires manufacturers to bear strict liability for defective products.
• Public policy requires strict innkeeper liability due to extraordinary guest vulnerability to fraud
• Questioning expert witnesses’ expertise or incentives is fair game in cross-examination
• Racial school segregation generates lasting feelings of inferiority among minority children
• Ratemaking methods are legally judged solely by whether their results are compensatory.
• Reasoning requires recognizing real logical connections and relationships among facts
• Redaction must not significantly alter the meaning of a defendant statement
• Reflective thinking connects known facts to unknown conclusions through inferences
• Reflective thought forms a chain of linked units toward a common end
• Reflective thought transforms obscurity and conflict into clarity and coherence
• Relevant geographic market definition is a question of fact, not law
• Relying on isolated phrases ripped from context commits a fallacy
• Removing a statement from context changes its intended meaning
• Requiring a single yes-or-no answer to a compound question smuggles in an unproven assumption
• Selecting a major premise depends on value judgments rather than strict logic
• Separate educational facilities in public schooling are inherently unequal
• Sequence alone never establishes causation as a matter of law
• Several early states granted free Black residents equal voting rights
• Shared context does not establish a causal or contractual connection between events
• Social and economic legislation requires only a rational relation to validity.
• Sound legal arguments require both valid reasoning and true premises
• Specific constitutional amendments collectively create distinct protected zones of privacy.
• State taxation of federal institutions lacks constituent representation that federal taxation possesses
• Statutes of limitations may be tolled by late discovery of injury
• Statutory silence on a question delegates discretion to the administrative agency.
• Steamboats furnishing rooms function as floating inns demanding identical legal duties
• Stereotypical assumptions about female vulnerability fail to justify gender-based employment restrictions
• Strict tort liability applies to non-profit distributors of defective products
• Studying logic trains reasoning power more than memorizing its rules
• Subject matter jurisdiction is a discrete threshold matter in federal courts
• Syllogistic validity requires each term keep one consistent sense
• The 1936 Literary Digest poll famously failed because its sample population was unrepresentative.
• The ability to study law depends on recognizing logical connections in cases
• The common law adapts to social and economic change
• The converse fallacy of accident arises from generalizing from inadequate instances.
• The Gitlow Court assumed incorporation without reasoned justification
• The high deference usually reflected in ‘rationality review’ represents a recognition that courts might misunderstand the facts, and that when the facts are unclear, judgments of value should be…
• The legal form of composition fallacies moves from specifics to generalities.
• The majority’s sweeping factual premise about all states is contradicted by historical evidence
• The middle term must be distributed in at least one premise
• The past informs the individual but can be re-captured through successive choices.
• The quality of a categorical proposition determines whether its predicate term distributes.
• The quantity of a categorical proposition determines its subject term distribution.
• The rising-middle-class narrative is unsupported by historical evidence
• The scope and meaning of legal rules depend on factual similarities
• The subject term of a universal proposition is always distributed
• This is Tushnet’s move in the debate about the counter-majoritarian objection to judicial review. I have given an argument that shows that what we thought were issues crucial to legitimacy were…
• Treating shared class membership as complete identity causes invalid reasoning
• Two negative premises prevent any logical determination of class relations
• Vague legal standards invite courts to beg the question
• Valid legal analogies depend on relevant similarities rather than case quantities
• Valid purposes in two distinct legal contexts do not justify merging them
• Valid syllogisms require every term used consistently throughout
• Validity of a syllogism relates exclusively to form rather than content
• White colonial education internalized self-hatred among West Indian Blacks.
• Written constitutions require that any repugnant legislative acts are void