Philosophical techniques for problem solving and exploration.

Introduction: What do philosophical techniques amount to?
Begging the question: The central role of asking.
Categories: Did I miss something?
Using tables: Noughts and crosses.
Possibility conditions: How sure can we be?
Phenomenology: Let the appearances speak.
Narrative methods: Think of a story to tell.
Fallacies: How to cloud the issue.
Conclusion: Common sense still required.

Philosophical techniques for problem solving and exploration.

What can we learn from two and a half millennia of philosophy?

Overhead sheets of a lecture held on May 8, 1998.

naar boven

Introduction: What do philosophical techniques amount to?

Scientific methods:

  • Mostly used for problem solving (answering a specific question).

“Philosophical” (generally applicable) techniques:

  • Problem solving: Ways to divide the problem into subproblems, ways to look for possible answers.
  • Exploration (looking for new possibilities): How to find new ways to use existing concepts, how to find new concepts.

  • There are no philosophical methods.
  • There are no philosophical proofs.
  • Methods and proofs are subject to rules.
  • Rules are objects of philosophical consideration.
  • What are the rules to deal with rules?

There are however quite general ways to find out facts and to convince yourself and others of their truth.

naar boven

Begging the question: The central role of asking.

Socrates (470-399 b.C): Anamnesis: finding out by asking questions. (Plato: Socratic dialogues)

You already know everything there is to know, you just have to become aware of it.

Concentrate on finding questions, not answers.

Meno: How to divide a square into two equal squares.

Every question may give rise to new questions.
Where does this lead to?

The classical final questions of philosophy:

  • Ontology: What is the world made of?
  • Epistemology: What can we know?
  • Antropology: What is man?
  • Ethics: How should we behave?
  • Aesthetics: What is art?
  • The ultimate question: Why is there something at all? (Leibniz / Heidegger)

naar boven

Categories: Did I miss something?

Have I considered all relevant aspects? Example: Detective (means, motive and opportunity).

Aristotle (384-322 b.C), universal genius (logic, rhetoric, metaphysics, natural sciences)


  • substance: what?
  • quantity: how much?
  • quality: what properties?
  • relation: associated with?
  • place: where?
  • time: when?
  • position: what situation?
  • condition: circumstances?
  • action: doing what?
  • affection: undergoing?

Categories of Immanuel Kant (1724-1804 AD)

Quality Quantity Relation Modality
affirmative universal categorical problematic
negative particular hypothetic assertoric
inifinite singular disjunctive apodictic

naar boven

Using tables: Noughts and crosses.

(cf. Carnaugh diagrams)

Kinds of people (E.W. Dijkstra):

Stupid Smart
Lazy innocent useless
Active dangerous useful


Prescriptive Descriptive
Regulative soccer thermodynamics
Constitutive chess Newtonian mechanics

Orthogonality: When the value in one category changes, should other values change too? (X = interaction)

Quality Quantity Relation Modality
Modality X X X
Relation X X
Quantity X

naar boven

Possibility conditions (Kant): How sure can we be?

e.g. What makes it possible for us to speak about weeds and crops? (Monoculture, harvesting methods, selective breeding, competion for natural resources, ..)

Necessary and sufficient conditions (-> means implication):

  • “A is necessary for P” means: ¬A -> ¬P
  • “B is sufficient for Q” means: B -> Q

Example: (A | B) & C <-> P
(| disjunction, & conjunction, <-> equivalence)

  • C necessary for P
  • P contingently dependent upon A and B
  • A&C or B&C sufficient for P.

naar boven

Dialectic: Venturing into the unknown.

Georg Wilhelm Friedrich Hegel (1770-1831): Dialektik
Uniting opposites.

Analysis Synthesis
analysis synthesis
Divide problem into ever smaller subproblems
  • Find an opposite
  • Look for commonalities
  • And repeat …

cf. Negotiations, legal trial.

naar boven

Phenomenology (Edmund Husserl, 1859-1938 AD): Let the appearances speak.

  • Admit all appearances, even those that can’t be explained.
  • Do not analyze or criticize.
  • Take those appearances as a starting point for enquiry.


  • “Meaning is use” (Ludwig Wittgenstein): Starting from the actual use of language, what can we say about meaning? (Why should language be illogical?)
  • The carpenter knows how to use a hammer without any knowledge of physics (Heidegger).

naar boven

Narrative methods: Think of a story to tell.

  • Plato and others: thought experiments
  • Gadamer: hermeneutics
  • Derrida: deconstructivism

Thought experiments: Plato’s cave, More’s utopia, Abbott’s Flatland, Rawls’ original position, Searle’s Chinese room, etc.

To be used to make up one’s mind or to convince others, in preparation of real experiments or instead of experiments where these are impossible.

naar boven

Fallacies: How to cloud the issue.

Typology of fallacies (Aristotle and others):

  • Non sequitur: John takes an umbrella when he wants to go out and it rains. John takes an umbrella now, so it is raining.
  • Many questions fallacy: Have you stopped beating your wife?
  • Petitio principii: I am glad that I don’t like spinach, because if I liked it I would have to eat it.
  • Composition fallacy: I fit into my coat. My coat fits into my bag. So I fit into my bag.
  • Etc.

naar boven

Conclusion: Common sense still needed.

These methods and techniques do not provide guarantees for useful or correct results. They are no alternatives for common sense but are only useful as a support in the process of finding answers.