In the past decades, reductionism has dominated both research directions and funding policies in clinical psychology and psychiatry. The intense search for the biological basis of mental disorders, however, has not resulted in conclusive reductionist explanations of psychopathology. Recently, network models have been proposed as an alternative framework for the analysis of mental disorders, in which mental disorders arise from the causal interplay between symptoms. In this target article, we show that this conceptualization can help explain why reductionist approaches in (...) psychiatry and clinical psychology are on the wrong track. First, symptom networks preclude the identification of a common cause of symptomatology with a neurobiological condition; in symptom networks, there is no such common cause. Second, symptom network relations depend on the content of mental states and, as such, feature intentionality. Third, the strength of network relations is highly likely to depend partially on cultural and historical contexts as well as external mechanisms in the environment. Taken together, these properties suggest that, if mental disorders are indeed networks of causally related symptoms, reductionist accounts cannot achieve the level of success associated with reductionist disease models in modern medicine. As an alternative strategy, we propose to interpret network structures in terms of D. C. Dennett's (1987) notion ofreal patterns, and suggest that, instead of being reducible to a biological basis, mental disorders feature biological and psychological factors that are deeply intertwined in feedback loops. This suggests that neither psychological nor biological levels can claim causal or explanatory priority, and that a holistic research strategy is necessary for progress in the study of mental disorders. (shrink)

We address the commentaries on our target article in terms of four major themes. First, we note that virtually all commentators agree that mental disorders are not brain disorders in the common interpretation of these terms, and establish the consensus that explanatory reductionism is not a viable thesis. Second, we address criticisms to the effect that our article was misdirected or aimed at a straw man; we argue that this is unlikely, given the widespread communication of reductionist slogans in psychopathology (...) research and society. Third, we tackle the question of whether intentionality, extended systems, and multiple realizability are as problematic as claimed in the target article, and we present a number of nuances and extensions with respect to our article. Fourth, we discuss the question of how the network approach should incorporate biological factors, given that wholesale reductionism is an unlikely option. (shrink)

The pivotal problem of comorbidity research lies in the psychometric foundation it rests on, that is, latent variable theory, in which a mental disorder is viewed as a latent variable that causes a constellation of symptoms. From this perspective, comorbidity is a (bi)directional relationship between multiple latent variables. We argue that such a latent variable perspective encounters serious problems in the study of comorbidity, and offer a radically different conceptualization in terms of a network approach, where comorbidity is hypothesized to (...) arise from direct relations between symptoms of multiple disorders. We propose a method to visualize comorbidity networks and, based on an empirical network for major depression and generalized anxiety, we argue that this approach generates realistic hypotheses about pathways to comorbidity, overlapping symptoms, and diagnostic boundaries, that are not naturally accommodated by latent variable models: Some pathways to comorbidity through the symptom space are more likely than others; those pathways generally have the same direction (i.e., from symptoms of one disorder to symptoms of the other); overlapping symptoms play an important role in comorbidity; and boundaries between diagnostic categories are necessarily fuzzy. (shrink)

The majority of commentators agree on one thing: Our network approach might be the prime candidate for offering a new perspective on the origins of mental disorders. In our response, we elaborate on refinements (e.g., cognitive and genetic levels) and extensions (e.g., to Axis II disorders) of the network model, as well as discuss ways to test its validity.

'Uncertainty and chance' is a subject with a broad span, in that there is no academic discipline or walk of life that is not beset by uncertainty and chance. In this book a range of approaches is represented by authors from varied disciplines: natural sciences, mathematics, social sciences and medical sciences. At one extreme, this volume is concerned with the foundations of probability. At the other extreme, we have scholars who acknowledge the concept of chance and uncertainty but do not (...) cope with it by means of systematic measurement or quantative analysis. (shrink)

Les textes présentés dans ce volume sont ceux des conférences prononcées en séance plénière dans le cadre du XXVIe Congrès international de Philosophie de Langue Française , consacré, pour marquer le quatrième centenaire de la naissance de Descarte, au thème général « L’esprit cartésien », et organisé du 30 août au 3 septembre 1996, en Sorbonne et au Palais de l’UNESCO, par la Société Française de Philosophie.Le volume est complété par une version en langue française des contributions à un Hommage (...) international à Descartes, prononcées, dans leurs langues respectives, lors de la séance de clôture du Congrès.Un CD-Rom présentant la version intégrale des Actes du Congrès est joint à ce volume, dont il constitue le complément nécessaire. (shrink)

If the density matrix is treated as an objective description of individual systems, it may become possible to attribute the same objective significance to statistical mechanical properties, such as entropy or temperature, as to properties such as mass or energy. It is shown that the de Broglie--Bohm interpretation of quantum theory can be consistently applied to density matrices as a description of individual systems. The resultant trajectories are examined for the case of the delayed choice interferometer, for which Bell [Int. (...) J. Quantum chem. 155--159, (1980)] appears to suggest that such an interpretation is not possible. Bell’s argument is shown to be based upon a different understanding of the density matrix to that proposed here. (shrink)

The formulae advanced by Popper to calculate the degree of corroboration C of a scientific hypothesis are unsatisfactory in that the probability values required in the computation are often not available. An attempt is made to define a quantitative measure B* in the place of C in which only countable empirical values would be used. This condition is fulfilled in two basic formulae and eq. ), which could be applied to calculate the degree of corroboration. When m successful falsifications of (...) the hypothesis h appear after a sequence of n unsuccessful ones, the pragmatic degree of corroboration B* results from the difference between B and the analogue value of the falsification F* and eq. ). In the event that the hypothesis can be "rescued" through a correction, increased experimental effort must be made with the revision. This would be taken into account through the correction equation ). When the hypothesis cannot be corrected, however, it can no longer exceed the value of 1-F*, even after numerous verification experiments. In the process of deciding whether a hypothesis is "adequately" verified or falsified, a lower threshold ${\rm B}_{{\rm u}}$ und Bₒ must be selected. These values have to be chosen on an intuitive subjective basis. The same applies to the strength of unsuccessful falsifications . This evaluation is expressed by a multiplicative constant a̱ ) or an additive constant kₐ in eq. . Despite the subjectivity of the values a̱, kₐ necessary for the calculation of B*, and of the values ${\rm B}_{{\rm u}}$ , Bₒ for the decision to discontiue the examination of the hypothesis, I feel that amongst the scientists within a particular field of research, a consensus for these values should be possible. Through a quantitative determination of B* the procedure for testing a hypothesis, considered to be a closed loop process, becomes clearer. To estimate the values of B* could not only have an influence upon the decisions of the respective researchers or research groups examining a hypothesis, but also be of assistance in decisions regarding research grants when financial resources are limited. (shrink)

Herodotus tells us in book vii, ch. 220, that the Pythian priestess gave the Spartans a warning couched in hexameters, of which the second line begins ἢ μγα στυ ρικυδς. To this text the admirable commentary of How and Wells takes exception in the following note: ‘The synizesis στυ ρικυδς is intolerable. Read δμ' ρικυδς, στυ being a gloss, H. Richards, Cl. Rev. xix. 345.’ Doubtless this union of vowels is harder than that of υω in ρινων or in γενων (...) and δυωδεκμηνον, accepted by Christ in his edition of Pindar . Let us grant that from the point of view of elegance it is even intolerable; the question still remains, should the line be altered? (shrink)

‘Saepe stilum vertas’, says Horace; and he had excellent company in his friend Virgil, who wrote the Aeneid at the rate of only about 900 lines a year, and spent hours in licking his verses into shape. It would have been instructive to sit at the elbow of these two poets, to see what they altered and what they rejected. It is clear, e.g., that there were certain caesural arrangements which Virgil deliberately affected and others which he as deliberately avoided. (...) But what of the care taken by these and other classical authors in arranging sounds in relation to mood or idea? This present incomplete essay is written frankly with scepticism in regard to dogmatic comments on certain particular points. It has been perilously easy to frame legislation on the basis of a predilection bolstered up by one or two instances. Even in the field of syntax we have seen generalizations on too narrow a foundation. An editor of Andocides enunciates ‘a very important principle of the language, which is rigidly observed by the best writers; viz., that, when a participle and a verb of different government are referred to the same object, the case of that object depends on the participle and not at all on the verb… Shilleto's remarks on this point must be excused, as evidently written hastily.’ But a casual cast of the net brings up about a score of violations of this principle from Homer to Menander. Where does the editor propose to draw the line between the respectable and the declassé Greek writers? Aristophanes, though cited in support, is actually flagrantly lawless in the matter; and with him must go not only Homer and Hyperides but Sophocles, Euripides, Menander, Xenophon, Lysias, and Plato, leaving among the élite, as cited by this editor, only Thucydides, Antiphon, and Aeschines; and one is entitled to doubt even their rigid observance of the law until they have actually been brought to court. In problems of rhythm, also, one has to be careful to use evidence as against preconception. When an editor hacks and fits the dactylics of Ennius so as to eradicate all feet beginning with two short syllables, it is as impious as recarving a statue by Daedalus because it does not conform to the canon of Polyclitus; and one may be forgiven if now and then one interprets the editor's corr. in his apparatus criticus not as correxi but as corrupi. (shrink)

On Virgil's statement that in honour of Bacchus ‘Ausonii … coloni versibus incomptis ludunt’, Servius remarks: ‘id est, carminibus Saturnio metro compositis, quod ad rhythmum solum vulgares componere consuerunt….’Obviously Servius is drawing a distinction between the Saturnian and other metres, as well as between the ordinary man and the man of letters. The unlettered compose their verses in the Saturnian metre, which is founded on rhythmus alone; the literary circles write theirs on some other basis.

When Demosthenes brought Aeschines to trial on a charge of malfeasance as an ambassador, he made what seems now the astonishing declaration in connection with Aeschines' acting of the part of Creon in Sophocles' Antigone: ⋯στε γ⋯ρ δ⋯που το⋯θ' ὅτι ⋯ν ἅπασι τοῖς δρ⋯μασι τοῖς τραγικοῖς ⋯ξα⋯ρετ⋯ν ⋯στιν ὥσπερ γ⋯ρας τοῖς τριταγωνισ ταῖς τὺ τοὺς τυρ⋯ννους κα⋯ τοὺς τ⋯ σκ⋯πτρ' ἔχοντας εἰσι⋯ναι. Until the last generation this was taken at face value as indicating that of the three actors presenting a (...) tragedy the third was regularly assigned the part of royalty. But that the title rôle in such plays as Sophocles' Oedipus Tyrannus or an important character such as Creon in the Antigone should have been entrusted to the third ranking actor is incredible. How is the discrepancy to be explained? (shrink)

‘A foolish consistency is the hobgoblin’ not only ‘of little minds,’ but of some classically trained minds as well. And it is surprising to see how this has caused certain unevennesses in ancient authors to be trued up. Aristophanes, for example, we are toldby a late venerable scholar, never permits a change of meter in a single speech directed to the same person; and to get rid of the two deviations from this rule, the framer of it cut down the (...) seemingly good trochaic tetrameters in the Peace to iambic trimeters, and then put line 555 before line 553 and took the three lines 555, 553, 554 from Trygaeus and assigned them to the coryphaeus. It is conceivable that if we possessed the thirty-three lost comedies of Aristophanes the editor might have had more and harder surgery on his hands. (shrink)

Lindquist et al. present a strong case for a constructionist account of emotion. First, we elaborate on the ramifications that a constructionist account of emotions might have for psychiatric disorders with emotional disturbances as core elements. Second, we reflect on similarities between Lindquist et al.'s model and recent attempts at formulating psychiatric disorders as networks of causally related symptoms.