## If 0=1, then a `pure `Inhaltslogik' is impossible. Comments on Liske's critique of Leibniz's theory of concepts

Autor(en): | Lenzen, W |

Stichwörter: | Philosophy |

Erscheinungsdatum: | 2000 |

Herausgeber: | FRANZ STEINER VERLAG GMBH |

Journal: | STUDIA LEIBNITIANA |

Volumen: | 32 |

Ausgabe: | 1 |

Startseite: | 105 |

Seitenende: | 116 |

Zusammenfassung: | In a 1994 paper entitled `Ist eine reine Inhaltslogik moglich?' M. Liske attempted to show that Leibniz's theory of intensional concepts suffers from a serious inadequacy. Liske begins by defining the intension of a concept in two slightly different ways. Broadly conceived, Int(A) is the set of all concepts B which are contained in A, while in a narrow sense, Int*(A) consists of all such B other than A itself. These definitions entail that the tautological concept 0 has an empty intension in the narrow sense, i.e. Int*(0)=phi, while Int(0)=(0). Furthermore it follows (in conjunction with certain unproblematic assumptions about the intensions of negative concepts in general) that the intension* of a negated individual-concept also is empty. And from this Liske concludes that the intensions* of all negative concepts must be empty. This, however, is a fallacy which rests upon conflating the empty set, phi, with the non-empty set (phi), which contains phi as its only element. |

ISSN: | 00393185 |

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