Logical Reasoning

For each of the incomplete arguments in the left column, select the missing premise from the right column that, if assumed, allows the argument's conclusion to be properly drawn.

Neurobiologist: Cognitive psychologists have long maintained that rapid eye movement (REM) sleep is necessary for consolidating emotional memories, citing studies where subjects deprived of REM sleep performed poorly on subsequent emotional recall tests. However, this conclusion is premature. Subjects administered pharmacological agents that selectively suppress REM sleep without altering other sleep stages exhibit completely intact emotional memory consolidation. Therefore, the memory deficits observed in earlier studies were almost certainly caused by the general stress induced by the deprivation methods, rather than by the absence of REM sleep.

Which of the following most accurately describes the method of reasoning used by the neurobiologist?

Botanist: Any alpine plant that undergoes early budburst without a corresponding increase in foliar cuticle thickness will suffer extensive cellular necrosis if exposed to unseasonal late-spring freezes. Furthermore, any plant that suffers extensive cellular necrosis from late-spring freezes will experience a reduction in lifetime seed viability below the replacement threshold unless it can activate dormant meristem tissue. Southern dwarf willows invariably undergo early budburst in response to early-season warming, yet they completely lack dormant meristem tissue. Therefore, if unseasonal late-spring freezes occur in their habitat, southern dwarf willows will experience a reduction in lifetime seed viability below the replacement threshold.

The botanist's conclusion follows logically if which one of the following is assumed?

Archaeologist: Recent excavations at a Middle Pleistocene hominin campsite recovered over two thousand stone cutting flakes. Microscopic analysis of the strike platforms revealed that approximately 88 percent display asymmetric curvature characteristic of intentional detachment by a right-handed knapper. In modern humans, population-level right-handedness reflects left-hemispheric cerebral lateralization—a neural architecture critical for syntactic language. Therefore, these findings indicate that hominins at this site had already evolved left-hemispheric neural specialization linked to linguistic capability.

Which of the following, if true, most strongly supports the archaeologist's argument?

Match each administrative or legal decision with the general normative principle that most directly justifies it:

Consider the following argument:

Paleoanthropologist: Excavators at the cave site argue that the discovery of micro-incised bone tubes demonstrates that Upper Paleolithic hominins developed formal musical notation systems. However, this interpretation is unwarranted. Micro-computed tomography reveals that the incisions exhibit irregular spacing and microscopic striations identical to butchery-tool deflection marks rather than intentional measuring increments. Furthermore, while the hollowed bones could conceivably produce resonant acoustic frequencies when blown into, any slender, naturally marrow-hollowed avian ulna produces acoustic resonance regardless of whether it was intentionally shaped as an instrument. Thus, the artifacts provide no compelling evidence of symbolic or musical culture.

Match each statement from the argument on the left with its precise argumentative role or method of reasoning on the right.

A municipal policy research team is evaluating four arguments concerning urban infrastructure and planning. Match each argument on the left with its corresponding abstract logical pattern or fallacy on the right.

Tariq: Municipal water authorities should mandate the installation of dual-flush toilets in all newly constructed residential buildings. Dual-flush systems reduce daily domestic water consumption by up to thirty percent, which is essential for preventing regional water shortages.

Sonia: While conserving water is critical, dual-flush mechanisms frequently malfunction due to local mineral sediment, resulting in continuous, undetected leaks that waste more water than conventional low-flow fixtures. Consequently, requiring dual-flush systems will fail to alleviate regional water shortages.

Statement: Tariq and Sonia disagree over whether mandating dual-flush toilets in new residential construction will effectively help mitigate regional water shortages.

Paleobiologist: Some researchers hypothesize that the intricately folded internal shell walls (sutures) of ammonoids evolved primarily to prevent shell implosion under severe hydrostatic pressure in deep oceanic zones. However, recent finite-element biomechanical simulations reveal that wall fluting produces localized stress concentrations rather than dissipating uniform pressure across the shell circumference. Moreover, stratigraphic distributions establish that the taxa possessing the most elaborate suture patterns inhabited shallow epicontinental seas where hydrostatic depth pressure was negligible. Hence, deep-water pressure resistance cannot be the primary evolutionary explanation for complex ammonoid sutures.

Arrange the statements below to reflect the logical progression of the paleobiologist's method of reasoning, from the introductory premise to the final conclusion.

Urban Planner: Any historic district redevelopment proposal that mandates permeable stone pavements will significantly reduce seasonal urban stormwater runoff. Furthermore, every redevelopment proposal that significantly reduces seasonal urban stormwater runoff helps lower downstream municipal infrastructure costs. Therefore, any historic district redevelopment proposal that mandates permeable stone pavements will be granted expedited zoning authorization by the city council.

The conclusion of the urban planner's argument follows logically if which one of the following is assumed?

Geochemists analyzing vapor plumes venting from the fracture zones of an icy satellite observed elevated concentrations of molecular hydrogen and methane. Laboratory simulations establish that while hydrothermal serpentinization reactions produce abundant hydrogen, the abiotic reduction of dissolved carbon dioxide into methane proceeds far too slowly under the moon's inferred core temperatures to yield the observed methane concentrations. On this basis, the researchers conclude that biological methanogenesis by chemoautotrophic microorganisms in the sub-surface ocean is the primary source of the plume methane.

True or False: The finding that primordial methane trapped in sub-surface clathrate hydrates during the satellite's initial accretion would have completely decomposed and outgassed within the first billion years of the solar system's formation logically strengthens the researchers' conclusion.

Urban Planner: Many historical preservationists argue that converting decommissioned industrial waterfronts into commercial retail zones destroys their cultural value. However, this view fails to recognize that preserving the physical structures of these warehouses requires substantial recurring maintenance funds. Since private retail developers are required to finance structural restoration and maintain historical facades as a condition of their leases, allowing commercial redevelopment actually safeguards the physical heritage of the waterfront. Thus, permitting retail adaptation is often the most effective means of historical preservation.

Which of the following most accurately describes the role played in the urban planner's argument by the claim that allowing commercial redevelopment actually safeguards the physical heritage of the waterfront?

Ethics Analyst: Any algorithmic underwriting model that evaluates borrower risk primarily through secondary transaction data inevitably relies on unverified behavioral proxies. Furthermore, any underwriting model that relies on unverified behavioral proxies fails to satisfy the regulatory threshold for fair lending practices. Thus, any algorithmic underwriting model adopted by sovereign credit unions will fail to satisfy the regulatory threshold for fair lending practices.

The ethics analyst's conclusion follows logically if which one of the following is assumed?

Complete the archaeometrist's formal deductive argument by identifying the missing premise that logically guarantees the conclusion.

Municipal Administrator: In an effort to curb residential water waste during peak summer drought conditions, the city of Oakvale installed automated smart flow-meters in every home across District 4. Simultaneously, District 4 households were transitioned to a tiered pricing structure that imposed sharply higher per-gallon rates for usage exceeding a basic threshold. Over the following year, residential water consumption in District 4 decreased by 18 percent, whereas consumption in neighboring District 5, which retained flat-rate pricing and standard mechanical meters, remained unchanged. Therefore, the implementation of tiered pricing was the primary cause of the reduction in water waste in District 4.

Which of the following, if true, most strengthens the municipal administrator's argument?

Marek: Forest management agencies should suspend all prescribed burn programs in old-growth pine ecosystems during drought cycles. Although low-intensity fire reduces understory fuel load, severely dry soil conditions cause even controlled fires to destroy the subterranean mycorrhizal networks essential for mature tree survival.

Sari: Prescribed burning is indeed risky during extreme drought, but completely suspending it is far more dangerous. If understory fuels accumulate during extended dry periods, an inevitable lightning strike will ignite a catastrophic canopy fire that completely destroys both mature trees and mycorrhizal networks.

Match each proposition with the relationship between the positions taken by Marek and Sari.

Dr. Sonya: Municipalities should rely exclusively on algorithmic risk-assessment instruments to determine bail amounts for criminal defendants. Human judges consistently demonstrate cognitive biases and arbitrary sentencing disparities, whereas actuarial algorithms calibrated solely on historical recidivism data provide an objective, standardized metric of flight risk.

Marcus: Algorithmic tools merely codify and obscure the systemic inequities embedded within the historical arrest data used to train them. Far from producing objective fairness, substituting mathematical models for judicial discretion replaces visible human bias with an unreviewable illusion of neutrality.

The dialogue provides the strongest support for holding that Dr. Sonya and Marcus disagree over whether:

Legal Scholar: The new corporate transparency legislation will fail to deter illicit financial flows. The legislation requires shell companies to disclose their ultimate beneficial owners to a centralized registry, but it relies on self-reporting by the companies' registered agents. Since registered agents face minimal penalties for submitting fraudulent documents on behalf of their clients, they have little incentive to verify the accuracy of the beneficial ownership information they report.

Which of the following are assumptions on which the legal scholar's argument depends? (Select all that apply.)

Soren: Historic preservation boards should have the authority to block homeowners from replacing original single-pane timber windows with modern triple-pane insulated windows in designated heritage districts. Preserving the authentic visual character and craftsmanship of historic architecture is a public good that outweighs individual property owners' desires to reduce heating and cooling costs.

Linnea: While maintaining the architectural character of historic neighborhoods is a worthy civic goal, modern insulated windows can now be custom-fabricated to be visually indistinguishable from historic timber originals from the street level. Therefore, when a homeowner uses such visually identical energy-efficient replacements, historic preservation boards should have no authority to prohibit them.

Soren and Linnea's statements provide the strongest support for holding that they disagree about which one of the following?

Match each of the following research arguments with the supplementary finding that most effectively strengthens its causal conclusion.