85 Tools of Philosophical Argument
Philosophy is not only a set of conclusions. It is a set of moves — ways of getting from something granted to something not yet granted, and rules about what counts as getting there. This section sets out 85 of them, each shown working on a real case rather than described in the abstract.
How this list was made
What puts a method in this section
A method is here because it can be shown working. The spine of the section is the worked argument: every entry takes its method and runs it on a real question — a proposition, the steps in order, and where it lands. Modus ponens is not defined and left there; it is put to work and made to produce a conclusion you can agree with or reject.
That test was chosen over importance because it is checkable. A claim that a method matters cannot be verified or refuted; a claim that a method takes these steps and yields this conclusion can be, and the argument either runs or it breaks in front of you.
The three shapes
Every entry carries one of three shapes, and the numbers are what they are rather than what would look tidiest. Forty-three are sequences — procedures with steps, performed in order. Thirty-one are inferences, where the move is a form and the form can be written out in numbered premises. Eleven are devices, and they are the odd ones: Ockham's razor, the burden of proof, the veil of ignorance. A device is not a procedure at all. It is a rule about what an argument is allowed to do, and it is filed as such rather than dressed up as a method to keep the columns even.
The six bands
Forms of inference · Classical procedures · Analytic tools · Continental procedures · Non-Western procedures · Devices and constraints.
The Non-Western band holds fifteen entries and is not an appendix to the others. Anumāna, the Indian inference, runs to five steps where Aristotle's syllogism runs to three, and it was set out around 200 BCE, a century and a half after the Prior Analytics, with no evidence that either side knew of the other. The catuṣkoṭi allows four positions where the logic of the first band allows two. These are not variants of the Greek material. They are separate solutions to the same problem, and placing them in a band of their own is the only arrangement that does not quietly make one of them the standard.
The oldest and the newest
Neti neti — the discipline of saying what a thing is not, because saying what it is will always say too much — is in the Upanishads by roughly 700 BCE. Conceptual engineering, which stops asking what a concept means and asks what it is for, arrives in 2000. Twenty-seven centuries separate them, and almost everything between is still in use: only two entries in the section are marked historical rather than live.
Where it fails
Every entry carries a block under that heading, and it is the block to read first if you are deciding whether to trust a method. It names the objection, names who raised it, and gives the case that raised it — Hume against induction, Duhem and Quine against the clean refutation, the false dilemma against the dilemma. A method you cannot break is a method you do not understand, and an atlas that presented eighty-five techniques as eighty-five reliable instruments would be lying about all of them.
What the section does not claim
It is a working set, not an inventory. Philosophy has no agreed list of its own methods, and any eighty-five are a selection with a hand behind it.
The line between a method and a doctrine is genuinely unclear in places, and where an entry sits close to it that is said in the entry rather than hidden. Dialectical materialism is a method of reading history and also a claim about history. The veil of ignorance is a device for testing rules and also an argument for particular ones.
Some words do double duty and the section does not tidy that away. Epoché names two different moves here — the sceptic's suspension of judgement and Husserl's bracketing of the world — and each entry says plainly which one it is and that the other exists.
Dates, and why some of them are hedged
Many of these dates mark when a method was first described, not when it was first used. Aristotle did not invent deduction in 350 BCE; he was the first to write down what people had been doing for centuries, and the entry says so. Where a date is a scholarly reconstruction rather than a record it is given as approximate, and it never carries an arithmetic that it cannot bear.
The arguments, and where they come from
The worked arguments are written for this Atlas. They are illustrations of the move rather than the historical example, except where an entry says otherwise — and where the historical case is the point, it is named and dated.
Entries are written against the standard reference literature, the Stanford Encyclopedia of Philosophy, the Internet Encyclopedia of Philosophy and Britannica, and checked against the primary texts wherever a method has a locus classicus. Corrections are welcome through the contact page.
Philosophy is not only a set of conclusions. It is a set of moves — ways of getting from something granted to something not yet granted, and rules about what counts as getting there. Each one is shown working on a real case rather than described in the abstract.
85 methods
FThe shapes an argument can take
Reductio ad absurdum
from 450 BCE
Induction
from 350 BCE
Deduction
from 350 BCE
Modal argument
from 350 BCE
Argument by analogy
from 350 BCE
Categorical syllogism
from 350 BCE
Modus ponens
from 300 BCE
Modus tollens
from 300 BCE
Disjunctive syllogism
from 300 BCE
Constructive dilemma
from 300 BCE
Hypothetical syllogism
from 300 BCE
Mathematical induction
from 1575
Probabilistic inference
from 1763
Transcendental argument
from 1781
Abduction
from 1878
CWhat the Greeks, the schoolmen and the early moderns actually did
Socratic elenchus
from 430 BCE
Aporia
from 400 BCE
Self-examination
from 399 BCE
Platonic dialectic
from 380 BCE
Diairesis
from 360 BCE
The infinite regress
from 350 BCE
Apodeixis
from 350 BCE
Genus and differentia
from 350 BCE
Endoxa
from 340 BCE
Pyrrhonian suspension
from 300 BCE
Sic et non
from 1120
The disputatio
1150 – 1650
Regressus
from 1450
Methodic doubt
from 1641
AThe instruments of twentieth-century philosophy
The thought experiment
from 450 BCE
Grounding
from 350 BCE
The counterexample
from 350 BCE
Necessary and sufficient
from 350 BCE
Distinction-drawing
from 350 BCE
The method of cases
from 1600
Objection and reply
from 1641
Debunking explanation
from 1841
Formalisation
from 1879
Conceptual analysis
from 1903
Logical form
from 1905
Verification
1929 – 1960
Ordinary language
from 1945
Explication
from 1950
Supervenience
from 1952
Possible worlds
from 1963
Reflective equilibrium
from 1971
Conceptual engineering
from 2000
CReading, unmasking, and starting again
The aphorism
from 1665
Immanent critique
from 1807
Sublation
from 1807
The hermeneutic circle
from 1819
Dialectical materialism
from 1845
Ideology critique
from 1845
Genealogy
from 1887
Eidetic variation
from 1913
The epoche
from 1913
Existential analysis
from 1927
Deconstruction
from 1967
Archaeology
from 1969
NIndia, China and the Islamic world
Neti neti
from 700 BCE
Zhengming
from 500 BCE
Lei
from 400 BCE
Catuṣkoṭi
from 400 BCE
Mīmāṃsā rules
from 200 BCE
Pūrvapakṣa and siddhānta
from 200 BCE
Upamāna
from 200 BCE
Śabda
from 200 BCE
Anumāna
from 200 BCE
Pratyakṣa
from 200 BCE
Pramāṇa theory
from 200 BCE
Prasaṅga
from 150
The kalām method
from 750
Ijtihād
from 800
Qiyās
from 800
DRules of engagement rather than procedures
Burden of proof
from 50 BCE
Ockham’s razor
from 1320
Ceteris paribus
from 1600
The state of nature
from 1651
Pascal’s wager
from 1662
Sufficient reason
from 1686
The is-ought gap
from 1739
Universalisability
from 1785
The open question
from 1903
The principle of charity
from 1959
The veil of ignorance
from 1971
Nothing matches those filters.