Argument and Thought Experiment Catalog

A reference catalog of canonical philosophical arguments, paradoxes, and thought experiments by name. Each entry gives the originator and year, a compressed statement of the structure (premises and conclusion or the scenario), the standard responses, and modern formulations. Use this when you need to cite “the Gettier case” or “the violinist” by source rather than re-explain the dialectic.

---

I. Arguments for the Existence of God

Argument	Originator + year	Structure	Standard responses	Modern formulations
Ontological (Anselmian)	Anselm, Proslogion 1078	God = “that than which nothing greater can be conceived”; if God existed only in the understanding, a greater being would be conceivable (one that also existed in reality); contradiction; so God exists in reality	Gaunilo’s “Perfect Island” reductio; Kant 1781 — existence is not a real predicate	Plantinga 1974 (The Nature of Necessity) modal-logic version: possibly God exists ⟹ God exists in some world ⟹ exists in all (necessary being)
Cartesian ontological	Descartes, Meditation V 1641	The idea of a supremely perfect being includes existence the way the idea of a triangle includes three sides	Hume — conceivability of non-existence; Kant’s predicate critique	(Largely subsumed into modal versions)
Gödel’s ontological	Gödel notebooks, c.1970; pub. Sobel 1987	Modal logic from positive properties: a being having all positive properties exists necessarily	Modal collapse: all truths become necessary (Sobel 1987)	Anderson 1990 modification avoids collapse; Benzmüller-Paleo 2014 machine-verified
Cosmological — First Way	Aquinas, Summa Theol. I q.2 a.3 (1265)	Things move; what moves is moved by another; regress impossible; so a first unmoved mover	Why no infinite regress? Why call the first cause God?	Aquinas’s full Five Ways; Feser 2017 retrieval
Kalām cosmological	al-Ghazali 1095; Craig 1979	Whatever begins to exist has a cause; the universe began to exist; so the universe has a cause	Quantum vacuum events; “begins” misused	Craig & Sinclair 2009 use Big Bang and Hilbert’s Hotel paradoxes
Leibnizian (from contingency)	Leibniz, Monadology 1714	Every contingent fact has a sufficient reason; the existence of the contingent universe needs a non-contingent reason — God	PSR may be false; brute-fact universe	Pruss 2006; Koons 1997
Teleological (design)	Cicero; Paley 1802 (Natural Theology)	A watch implies a watchmaker; nature shows comparable design; so nature has a designer	Darwin 1859; Hume 1779 — could be many gods, or a bumbling one	Behe 1996 (intelligent design); largely abandoned
Fine-tuning	Carter 1974; Leslie 1989; Collins 2009	Physical constants lie in a narrow life-permitting range; chance and necessity fail; design is the best explanation	Multiverse; weak anthropic principle; what’s the right reference class?	Collins 2009; Hawthorne & Isaacs 2018 Bayesian version
Moral argument	Kant, Critique of Practical Reason 1788; C. S. Lewis 1952 (Mere Christianity); Craig 1989	Objective moral values exist; they require a transcendent ground; so God exists	Moral realism without theism (Wielenberg, Enoch); evolutionary debunking	Craig & Sinnott-Armstrong 2004 debate
Pascal’s Wager	Pascal, Pensées §233 (1670)	Decision-theoretic: belief dominates given infinite payoff; so wager for God	Many-gods objection; cannot will belief; mixed strategies	Hájek 2003 dominance analyses

II. Arguments Against the Existence of God

Argument	Originator + year	Structure	Standard responses	Modern formulations
Logical problem of evil	Epicurus (attrib.); Mackie 1955 (“Evil and Omnipotence”)	(1) Omnipotent + omniscient + omnibenevolent God is incompatible with any evil	Plantinga 1974 free-will defense — God’s creating free creatures may make some evil unavoidable	(Most philosophers grant Plantinga’s defense logically succeeds)
Evidential problem of evil	Rowe 1979 (“The Problem of Evil and Some Varieties of Atheism”)	Gratuitous evils (e.g., fawn dying in unobserved forest fire) make theism improbable	Skeptical theism (Bergmann 2001) — we can’t see the goods God might be securing	Draper 1989 (Bayesian); Rowe 1996 reply
Skeptical theism	Wykstra 1984; Bergmann 2001	(Defense) We have no reason to think we can detect God’s reasons	Implies global skepticism about God’s communications and morality (Almeida-Oppy 2003)	Bergmann; Howard-Snyder
Theodicies	Augustine (privatio boni); Irenaeus / Hick 1966 (soul-making); Plantinga 1974 (free-will defense); Swinburne 1998	Various positive accounts of why God permits evil	Each addresses only a subset of evils	Plantinga; Hick; Swinburne; Stump 2010
Divine hiddenness	Schellenberg 1993 (Divine Hiddenness and Human Reason)	A perfectly loving God would not permit non-resistant non-belief; such non-belief occurs; so no such God	Replies in terms of soul-making, free response	Schellenberg 2015 update

III. Epistemology

Case	Originator + year	Structure	Responses	Modern formulations
Gettier cases	Gettier 1963 (“Is Justified True Belief Knowledge?“)	Smith-Jones / Brown-in-Barcelona: justified true belief that fails to be knowledge because the truth obtains via a non-connected route	”No false lemmas” (Clark); causal connection (Goldman 1967); safety (Sosa, Williamson); sensitivity (Nozick)	Pritchard 2005 (anti-luck); Williamson 2000 (knowledge-first)
Fake-barn / Barn-Façade	Goldman 1976 (attr. Ginet)	Henry sees a real barn in a county of fake-barn façades; the belief is true and justified but intuitively not knowledge	Sosa’s safety; Pritchard’s modal account	Sosa 2007; Pritchard
Brain-in-a-vat	Putnam, Reason, Truth and History 1981	If I were a BIV stimulated by computers, “I am a BIV” said by me would be false (semantic externalism); so I am not a BIV	Replies require accepting Putnam’s externalism; Cartesian skeptic restates in non-semantic terms	Pryor’s “dogmatism”; Wright transmission failure
Twin Earth	Putnam, “The Meaning of ‘Meaning’” 1975	On Twin Earth water = XYZ; my and twin-me’s narrow “water”-thoughts differ in reference, so meaning is not in the head	Internalist replies (Searle); narrow content (Fodor)	Burge 1979 social externalism; foundation for externalism in philosophy of mind
Cartesian demon	Descartes, Meditation I 1641	A powerful deceiver could be making me wrong about everything except cogito	Moorean response (Moore 1939); reliabilism; contextualism	Stroud 1984 sustained version
Moorean response	Moore, “Proof of an External World” 1939	Here is one hand, here is another, so there are external objects	Begs the question against skeptic; underestimates skeptical scenarios	Pryor 2000 dogmatism; Wright 2004
Closure paradox	Dretske 1970; Nozick 1981	I know I have hands; “I have hands” entails “I am not a handless BIV”; do I therefore know I am not a BIV?	Reject closure (Nozick, Dretske); reject skepticism (Moore)	DeRose 1995 contextualist resolution
Lottery paradox	Kyburg 1961	I justifiedly believe of each ticket that it will lose; conjoining gives belief in a contradiction	Reject conjunction; subjective probability	Hawthorne 2004
Preface paradox	Makinson 1965	Author rationally believes each claim in the book yet acknowledges in the preface that some must be false	Threatens conjunctive belief closure	Christensen 2004

IV. Ethics and Decision Theory

Case	Originator + year	Structure	Responses	Modern formulations
Trolley problem (Switch)	Foot 1967 (“The Problem of Abortion and the Doctrine of Double Effect”)	Divert trolley to kill one to save five — permissible? Most: yes	Doctrine of Double Effect (Aquinas); Kantian use-as-mere-means	Edmonds 2013 (Would You Kill the Fat Man?); empirical moral psychology
Trolley problem (Footbridge)	Thomson 1976 (“Killing, Letting Die, and the Trolley Problem”)	Push large stranger off bridge to stop trolley — permissible? Most: no	Personal-force; doing vs allowing; Kantian use-as-means	Greene 2008 dual-process moral psychology
Loop case	Thomson 1985	Side track loops back so the one is needed (not merely foreseen) to stop the trolley	Tests whether merely-foreseen-vs-intended is doing work	Thomson 2008 (later argued switch is impermissible too)
Violinist	Thomson 1971 (“A Defense of Abortion”)	You wake hooked to a famous violinist who will die unless you stay connected nine months; permissible to unplug?	Disambiguates “right to life” from “right to use another’s body”	Boonin 2002 defense; Beckwith 1992 critique
Drowning child	Singer 1972 (“Famine, Affluence, and Morality”)	If you can save a drowning child at small cost, you must; distant strangers are morally similar	Demandingness; partial duties; agent-centered options	Unger 1996 (Living High and Letting Die); MacAskill effective altruism
Survival lottery	Harris 1975	Random selection of one person to be killed for organs to save several — should we adopt?	Distinct kind of killing; trust collapse; bodily integrity	(Used to probe utilitarianism)
Experience machine	Nozick, Anarchy, State, and Utopia 1974 §III	Would you plug in for guaranteed pleasant simulated experience? Most: no	Refutes hedonism about well-being	Crisp 2006 reply; Lin 2016
Pleasure receptacle	Nozick 1989 (Examined Life)	Two creatures with same pleasure; one is rich in achievement	Bears on objective list theories	Crisp; Sumner
Repugnant conclusion	Parfit, Reasons and Persons §17 (1984)	For any population A with high welfare, there is some Z with low-positive welfare but more people that is better in total	Person-affecting principles; critical-level utilitarianism	Arrhenius 2000s population axiology
Non-identity problem	Parfit 1984 §16	Choosing a policy that makes people exist who could not otherwise — they aren’t harmed	Bears on climate, reproduction	Boonin 2014
Mere addition	Parfit 1984	Adding lives barely worth living seems neutral, yet generates the repugnant conclusion	Arrhenius 2000 impossibility theorems
Prisoner’s Dilemma	Flood-Dresher 1950; Tucker 1950 (named)	Two prisoners; each defects rationally yet jointly worse	Iterated PD with tit-for-tat (Axelrod 1984); evolution of cooperation	Skyrms 1996; Bicchieri 2006
Newcomb’s problem	Nozick 1969 (attrib. Newcomb)	One-box for $1Mpredictedortwo-boxforthevisible$1k + whatever was predicted; CDT vs EDT diverge	Causal vs evidential decision theory; FDT (Yudkowsky 2017)	Joyce 1999; Ahmed 2014
Original position / Veil of Ignorance	Rawls, A Theory of Justice 1971	Behind a veil hiding personal attributes, rational agents would choose two principles: liberty + difference	Nozick: ahistorical; Sandel: thin self; communitarian critique	Scanlon 1998 contractualist relative; Rawls 1993 reformulation
Wilt Chamberlain	Nozick 1974	Voluntary transactions disrupt patterned distributions of justice	Reply: regulate transactions, not pattern	Cohen 1995 critique

V. Mind, Language, and Persons

Case	Originator + year	Structure	Responses	Modern formulations
Chinese Room	Searle 1980 (“Minds, Brains, and Programs”)	Person in a room follows rules to manipulate Chinese symbols, passes the Turing test, but understands nothing; so syntax ≠ semantics; strong AI false	Systems reply; robot reply; brain-simulator reply	Searle 1992; Block 1995; reignited by LLMs
Turing test	Turing 1950 (“Computing Machinery and Intelligence”)	If a machine’s textual responses are indistinguishable from a human’s, it should be counted as thinking	Searle’s Chinese Room; behaviorism in disguise	Levesque 2017 Winograd schemas; large-language-model debate
Bat	Nagel 1974 (“What Is It Like to Be a Bat?“)	We cannot imaginatively occupy the bat’s sonar phenomenology; so subjective character of experience is irreducible	Lewis 1990 “knowing what it’s like” as ability	Chalmers 1996 hard-problem precursor
Zombies (philosophical)	Kirk 1974; Chalmers, The Conscious Mind 1996	A creature physically identical to me but lacking phenomenal consciousness is conceivable; so consciousness is not entailed by the physical	Dennett 1991, 1995 (“zombie hunch” is unreliable); type-B physicalism (Block-Stalnaker)	Kirk 2005; Chalmers 2010
Mary’s Room (knowledge argument)	Jackson 1982 (“Epiphenomenal Qualia”)	Mary the colour-vision scientist knows all physical facts about colour but learns something new when she first sees red	Lewis-Nemirow ability hypothesis; Loar phenomenal-concept strategy; Jackson 1998 recantation	Stoljar 2005; Alter 2007
Inverted qualia	Locke 1689; Block 1990	Two people’s qualia could be systematically inverted with identical behavior	Functionalist replies (Shoemaker); panpsychist replies	Shoemaker 1982; Tye 1995
Swampman	Davidson 1987 (“Knowing One’s Own Mind”)	Lightning hits a swamp; a molecule-for-molecule Davidson-replica forms; does it mean anything by its utterances?	Tests externalism: Davidson says no	Block, Fodor on content
Floating man	Avicenna, De Anima c.1027	A man created in midair with no sensory input still affirms his own existence; so self-knowledge is independent of body	Anticipates Cartesian cogito	Black 1993
Cogito	Descartes, Meditation II 1641 (“I think, therefore I am”)	Even radical doubt cannot doubt the thinker; so I exist as a thinking thing	Hume 1739 — bundle theory denies enduring “I”; Lichtenberg — should be “there is thinking”	Williams 1978; Markie 1992
Ship of Theseus	Plutarch, Vita Thesei c.75 CE; Hobbes 1655 (planks reassembled)	Replace each plank; reassemble removed planks into another ship; which is the original?	Identity over time; 4-D worm/stage theories	Wiggins 1980; Sider 2001
Personal-identity reduplication	Williams 1970; Parfit 1984	Brain-duplication scenarios show personal identity is not what matters	Reductionism (Parfit); animalism (Olson)	Olson 1997; Shoemaker 1984
Statue and clay	Gibbard 1975 (“Contingent Identity”)	Clay statue and lump of clay coincide; share location and mass; differ in survival conditions	Constitution view (Baker); 4D-stage; mereological essentialism	Baker 2000; Wasserman 2018
Twin Earth (linguistic)	Putnam 1975	(See above)	(See above)	Externalism in language and mind

VI. Paradoxes and Puzzles

Paradox	Originator + year	Structure	Responses
Sorites (heap)	Eubulides, c.4th c BCE	One grain isn’t a heap; adding one grain to a non-heap never makes a heap; so 10,000 grains is no heap	Epistemicism (Williamson 1994); supervaluationism (Fine 1975); degree theories
Liar	Eubulides; Epimenides legendarily	”This sentence is false”: true iff false	Tarski 1933 hierarchy; Kripke 1975 fixed-point; revision theory (Gupta-Belnap 1993); paraconsistent (Priest 1979 dialetheism)
Russell’s paradox	Russell 1901 (letter to Frege 1902)	The set of all sets not members of themselves: R ∈ R iff R ∉ R	Type theory (Russell-Whitehead); ZFC axiom of foundation; Quine NF
Grelling-Nelson (heterological)	Grelling & Nelson 1908	Is “heterological” (= not self-applying) heterological?	Like Russell at the predicate level
Berry paradox	Russell 1908 (after Berry)	“The smallest positive integer not definable in fewer than twelve words” — definable in eleven	Distinguishes object/meta language; Chaitin complexity
Burali-Forti paradox	Burali-Forti 1897	The ordinal of all ordinals is greater than every ordinal	Resolved by ZFC class-set distinction
Cantor’s paradox	Cantor 1899	Power set of universe is larger than universe	Same resolution as Burali-Forti
Zeno’s Achilles	Zeno of Elea, c.450 BCE; rep. by Aristotle	Achilles can never overtake the tortoise because he must first reach where it was	Convergent infinite series; Aristotle’s potential infinity
Dichotomy	Zeno c.450 BCE	To travel a distance, must traverse half first, then half of remainder, ad infinitum	Same as above
Arrow paradox	Zeno c.450 BCE	At any instant the arrow is motionless; sum of motionless instants gives no motion	Calculus; instantaneous velocity
Stadium	Zeno c.450 BCE	Relative motion of equal bodies at equal speeds yields a contradiction	Resolves with relative velocity
Two envelopes	Nalebuff 1989	Switching seems to dominate but symmetry forbids	Probability axiomatics; improper priors
Sleeping Beauty	Elga 2000	Beauty wakes once (heads) or twice (tails); credence for heads on waking?	Thirders (Elga, Lewis 2001) vs halfers (Lewis revised; Bostrom)
Doomsday argument	Carter 1983; Gott 1993; Leslie 1996	Self-sampling: I am likelier to find myself among many humans than few; updates toward early extinction	Reference-class problem; Bostrom 2002

VII. Political and Social

Case	Originator + year	Structure	Responses
State of nature	Hobbes Leviathan 1651; Locke Two Treatises 1689; Rousseau 1755	A hypothetical pre-political condition motivates the social contract	Each thinker draws very different lessons (war of all vs orderly liberty vs corrupted innocence); historical critiques (anthropology)
Sexual contract	Pateman, The Sexual Contract 1988	The original contract subordinates women; standard contract theory hides this	Reshapes liberal contractarianism
Racial contract	Mills, The Racial Contract 1997	A historical agreement among whites to categorize non-whites as sub-persons underlies the social contract	Reshapes liberal contractarianism
Tragedy of the commons	Hardin 1968 (Science)	Individually rational extraction destroys common resources	Ostrom 1990 — communities solve commons via institutions
Tyranny of the majority	Tocqueville 1835; Mill 1859	Majoritarian democracy can oppress minorities	Bills of rights; judicial review; consociationalism

---

Adjacent

• Philosopher catalog for the originators by surname and date.
• Philosophical positions catalog for the broader -isms these arguments defend.
• Schools and movements catalog for the traditions that generated them.
• Epistemology survey for the Gettier and skeptical arguments in context.
• Ethics survey for Trolley, Drowning Child, Original Position.
• Philosophy Tier 3 index · Philosophy Tier 1 root