• Back to Profile
    •  

     


    Si les prémisses d'un syllogisme sont toutes les deux à l'indicatif,
    la conclusion sera également à l'indicatif.
    Pour que la conclusion pût être mise à l'impératif,
    il faudrait que l'une des prémisses au moins fût elle-même à l'impératif.
    - Henri Poincaré's (1913) 'La Morale et la Science' in the original French

    If the premises are in the indicative mood,
    then the conclusion will be in the indicative mood too.
    For a conclusion in the imperative mood,
    At least one premise in the imperative mood will be required.
    - Personal translation

     

     

     

     

    Jørgensen's Dilemma
    Military poster
    1. In linguistics, a grammatical mood is a classification that signals modality and indicates the attitude of the speaker

    3. The 5 main grammatical moods are:
      1. The indicative mood — to express a fact;
      2. The imperative mood — to express a command or request;
      3. The interrogative mood — to express a sense of uncertainty by asking a question;
      4. The conditional mood — to express an if-then condition;
      5. The subjunctive mood — to express a wish, doubt, demand, or hypothetical situation.

    EXAMPLES of sentences in the indicative mood:

    EXAMPLES of sentences in the imperative mood
    (Jørgensen, 1937/1938):


    2. S1′: On the decibel scale, near total quiet is 0 dB.
    3. S2′: The door is made of knotty alder.
    4. S3′: Multiplication is one of the traditional arithmetic operations on numbers.
    5. S4′: The word 'silly' has 5 letters.
    6. S5′: 'Do your duty' is the title of a military poster at the Smithsonian National Museum of American History.
    7. S6′: The golden rule is a maxim that is found in many religious traditions.
    8. S7′: Kant's formula of universal law is one of four formulations of the categorical imperative.

    2. S1: Be quiet.
    3. S2: Shut the door, please.
    4. S3: Multiply 3 by 5.
    5. S4: Don't be silly.
    6. S5: Do your duty.
    7. S6: What you should not want done to yourself, do not do to others.
    8. S7: Act only on that maxim whereby thou canst at the same time will that it should become universal law.

    EXAMPLES of types of imperatives:

    An imperative expressing a fiat (impersonal)


    S8: Let there be light.


    An imperative expressing a directive (personal and single-agent)


    S9: Melvin, pass me the sunglasses.


    An imperative expressing a directive (personal and multi-agent)


    S10: Lois and Clark, carry the piano upstairs.


    An imperative expressing an unconditional prescription


    S11: Hug me.


    An imperative expressing a conditional prescription


    S12: If you would like to feel better, hug me.


    An imperative expressing a synchronic prescription


    S13: Meet me at 4 pm today.


    An imperative expressing a diachronic prescription


    S14: Meet me at 4 pm every Friday.


    An imperative expressing an unsatisfiable prescription (i.e. satisfaction is impossible)


    S15: Let 1 + 1 be 3.


    An imperative expressing an unviolable prescription (i.e. violation is impossible)


    S16: Let 1 + 1 be 2.


    An imperative expressing a thick prescription (i.e. incorporating second-best instructions)


    S17: Do not smoke; but if you do, at least smoke in moderation.



    Henri Poincaré (1854-1912)
    1. According to Henri Poincaré:
    2. All scientific sentences are in the indicative mood (expressing facts)
    3. Conversely, all moral sentences are in the imperative mood (expressing commands or requests)
    4. From sentences in the indicative mood, we can only derive conclusions in the indicative mood by logical inference
    5. C1 (Poincaré): ∴ It is impossible for imperative sentences to serve as the conclusions in inferences with indicative premises.
    6. C2 (Poincaré): ∴ It is impossible to found morals on science.

    1. According to H. W. B. Joseph:
    2. An inference is a process of thought that, starting with one or more judgments (viz. premise set), ends in another judgment (viz. conclusion set) whose truth is seen to be involved in that of the former

    1. A proposition is a sentence that is capable of bearing one of two truth values: T or 1 (for truth) or F or 0 (for falsity)
    2. An inference relation only holds between sentences that are propositions
    3. HOWEVER
    4. Imperative sentences do not appear to fulfil the condition of being truth-apt (i.e. either true or false)
    5. ∴ Imperative sentences do not appear to qualify as propositions or argumentative constituents
    6. S1 ('Be quiet') and S5 ('Do your duty') may be obeyed or disobeyed, accepted or not accepted, and justified or unjustified
    7. If we ask whether S1 and S5 are true or false, we would be asking meaningless questions

    9. C3 (Jørgensen): ∴ It is impossible for imperative sentences to serve as premises in inferences.
    10. C4 (Jørgensen, from C1 & C3): ∴ It is impossible for imperative sentences to function as an argumentative constituent.

    Jørgensen's dilemma

    2 Horns of Jørgensen's Dilemma


    Jørgensen (1937/1938, p. 290)

    HORN 1

    HORN 2

    Sentences in the imperative mood are not capable of being true or false

    1. ADVANTAGE with HORN 1: We can explain why the following questions are meaningless:
    2. Q1: Is S1 ('Be quiet') true or false?
    3. Q2: Is S5 ('Do your duty') true or false?

    1. DISADVANTAGE with HORN 1: We cannot explain why imperative sentences can be inferred from other sentences

    3. INFERENCE 1:
    4. P1: Keep your promises.
    5. P2: This is a promise of yours.
    6. C: ∴ Keep this promise.

    8. INFERENCE 2:
    9. P1: Love your neighbour as yourself.
    10. P2: Love yourself.
    11. C: ∴ Love your neighbour.
    Sentences in the imperative mood are capable of being true or false

    1. ADVANTAGE with HORN 2: We can explain why imperative sentences can be inferred from other sentences

    3. INFERENCE 1:
    4. P1: Keep your promises.
    5. P2: This is a promise of yours.
    6. C: ∴ Keep this promise.

    8. INFERENCE 2:
    9. P1: Love your neighbour as yourself.
    10. P2: Love yourself.
    11. C: ∴ Love your neighbour.

    1. DISADVANTAGE with HORN 2: We cannot explain why the following questions are meaningless:
    2. Q1: Is S1 ('Be quiet') true or false?
    3. Q2: Is S5 ('Do your duty') true or false?

     

     

    Background image taken from: https://cdn.asiatatler.com/asiatatler/i/th/2020/02/04101225-aurora-1185464-1920_cover_1920x1280.jpg This website has been coded using html, css, and js and is dedicated to B and H .