This paper investigates a limitation of the model of belief and knowledge prevailing in mainstream economics, namely the state-space model. Because of its set-theoretic nature, this model has difficulties in capturing the difference between expressions that designate the same object but have different meanings, i.e., expressions with the same extension but different intensions. This limitation generates puzzling results concerning what individuals believe or know about the world as well as what individuals believe or know about what other individuals believe or (...) know about the world. The paper connects these puzzling results to two issues that are relevant for economic theory beyond the state-space model, namely, framing effects and the distinction between the model-maker and agents that appear in the model. Finally, the paper discusses three possible solutions to the limitations of the state-space model, and concludes that the two alternatives that appear practicable also have significant drawbacks. (shrink)

Abstract The first part argues that being an image is an (at least) four part relation between the image itself (x2), properties of recipients (B), the object (x3), and properties of the object (M). Referring to Grice, Schiffer, and Meggle, a distinction is made between communicativity and non-communicativity (manipulativity) of x2 regarding to B, x3, and M. The second part substitutes sign and image by explicates that denote properties relevant for x2 being an image regarding to B, x3, and M, (...) making thus clear why images are signs. Intentional relations and causal relations are the basis of this explication (influenced by Posner) that is also meant to give an idea of those properties that are typical of pieces of fine arts and of some other cultural practices. Additionally, it helps in understanding the difference between typical images and more abstract symbols. -/- Im ersten Abschnitt werden Gründe dafür genannt, Bildsein als mindestens vierstellige Beziehung aufzufassen: als Beziehung zwischen dem Bild (x2), Rezipienteneigenschaften (B), dem Bildgegenstand (x3) und Eigenschaften (M) des Bildgegenstandes. Dabei wird – anknüpfend an Grice, Schiffer und Meggle – zwischen Kommunikativität und NichtKommunikativität (Manipulativität) von x2 bzgl. B, x3 und M unterschieden. Im zweiten Abschnitt wird die Rede von ›Zeichen‹ und von ›Bildsein‹ ersetzt durch Explikate, die Eigenschaften bezeichnen, welche relevant dafür sind, dass x2 ein Bild bzgl. B, x3 und M ist – derart, dass deutlich wird, inwiefern Bilder Zeichen sind. Basis dieser – von Posner angeregten – Explikationen sind intentionale Beziehungen und Bewirken. Aus den Begriffspräzisierungen ergeben sich Einsichten sowohl in Bezug auf Eigenschaften, die typisch für Werke Bildender Kunst und einige andere kulturelle Praktiken sind, als auch in Bezug auf eine Abgrenzung zentraler Vertreter der Kategorie ›Bild‹ von eher nur bildhaften Symbolen. (shrink)

There is an obvious difference between what a term designates and what it means. At least it is obvious that there is a difference. In some way, meaning determines designation, but is not synonymous with it. After all, “the morning star” and “the evening star” both designate the planet Venus, but don't have the same meaning. Intensional logic attempts to study both designation and meaning and investigate the relationships between them.