Copyright © 1999 Massachusetts Institute of Technology
Franz Brentano (1838-1917), German philosopher and psychologist, taught in the University of Vienna from 1874 to 1894. He is the author of Psychology from an Empirical Standpoint (first published in 1874), and is principally remembered for his formulation of the so-called Brentano thesis or doctrine of intentionality, according to which what is characteristic of mental phenomena is their INTENTIONALITY or the "mental inexistence of an object."
For Brentano, intentionality is to be understood in psychological (or in what might today be called methodologically solipsistic) terms. To say that a mental act is "directed toward an object" is to make an assertion about the interior structure or representational content of the act. Brentano's primary aim is to provide a taxonomy of the different kinds of basic constituents of mental life and of the different kinds of relations between them. Unlike more recent cognitive psychologists, Brentano takes as his main instrument in analyzing these basic constituents and relations not logic but a sophisticated ontological theory of part and whole, or "mereology." Where standard mereology is extensional, however, treating parts and wholes by analogy with Venn diagrams, Brentano's mereology is enriched by topological elements (Brentano 1987) and by a theory of the different sorts of dependence relations connecting parts together into unitary wholes of different sorts. A theory of "mereotopology" along these lines was first formalized by Husserl in 1901 in the third of his Logical Investigations (1970), and its application by Husserl to the categories of language led to the development of CATEGORIAL GRAMMAR in the work of Lesniewski and in Ajdukiewicz (1967).
The overarching context of all Brentano's writings is the psychology and ontology of Aristotle. Aristotle conceived perception and thought as processes whereby the mind abstracts sensory and intelligible forms from external substances. Impressed by the successes of corpuscularism in physics, Brentano had grown sceptical of the existence of any external substances corresponding to our everyday cognitive contents. He thus suspended belief in external substances but retained the Aristotelian view of cognition as a process of combining and separating forms within the mind. It is in these terms that we are to understand his view that "[e]very mental phenomenon includes something as object within itself" (1973).
Brentano distinguishes three sorts of ways in which a subject may be conscious of an object:
Brentano's theory of part and whole is presented in his Descriptive Psychology (1995). Many of the parts of consciousness are "separable" in the sense that one part can continue to exist even though another part has ceased to exist. Such separability may be either reciprocal -- as in a case of simultaneous seeing and hearing -- or one-sided -- as in the relation of presentation and judgment, or of presentation and desire: a judgment or desire cannot as a matter of necessity exist without some underlying presentation of the object desired or believed to exist.
The relation of one-sided separability imposes upon consciousness a hierarchical order, with ultimate or fundamental acts, acts having no further separable parts, constituting the ground floor. Such basic elements are for Brentano always acts of sensation. Even among basic acts, however, we can still in a certain sense speak of further parts. Thus in a sensation of a blue patch we can distinguish a color determination and a spatial determination as "distinctional parts" that mutually pervade each other. Another sort of distinctional part is illustrated by considering what the sensation of a blue patch and the sensation of a yellow patch share in common: they share, Brentano holds, the form of coloredness as a logical part. Brentano's account of the range of different sorts of distinctional parts of cognitive phenomena, and especially of the tree structure hierarchies manifested by different families of logical parts, covers some of the ground surveyed by later studies of "ontological knowledge" (Keil 1979).
Brentano's students included not only Sigmund Freud and T. G. Masaryk, but also Edmund Husserl, Alexius Meinong, Christian von Ehrenfels, and Carl Stumpf. Each went on to establish schools of importance for the development of different branches of cognitive science within this century (Smith 1994). Husserl's disciples founded the so-called phenomenological movement; Meinong founded the Graz School of "Gegenstandstheorie" (ontology without existence assumptions); and it was students of Ehrenfels and Stumpf in Prague and Berlin who founded the school of GESTALT PSYCHOLOGY (the term "Gestalt" having been first used by Ehrenfels as a technical term of psychology in 1890; see Ehrenfels 1988; MacNamara and Boudewijnse 1995). The representatives of each of these schools and movements attempted to transform Brentano's psychological doctrine of intentionality into an ontological theory of how cognizing subjects are directed toward objects in the world. The influence of Brentano's philosophical ideas is alive today in the work of analytic philosophers such as Roderick Chisholm (1982), and it has been especially prominent in twentieth-century Polish logic and philosophy (Wolenski and Simons 1989).
Ajdukiewicz, K. (1967). Syntactic connexion. In S. McCall, Ed., Polish Logic 1920-1939. Oxford: Clarendon Press, pp. 207 - 231.
Brentano, F. (1973). Psychology from an Empirical Standpoint. London: Routledge and Kegan Paul.
Brentano, F. (1987). Philosophical Investigations on Space, Time and the Continuum. London: Croom Helm.
Brentano, F. (1995). Descriptive Psychology. London: Routledge.
Chisholm, R. M. (1982). Brentano and Meinong Studies. Amsterdam: Rodopi.
Ehrenfels, C. von (1988). On "Gestalt Qualities." In B. Smith, Ed., Foundations of Gestalt Theory. Munich and Vienna: Philosophia, pp. 82-117.
Husserl, E. (1970). Logical Investigations. London: Routledge and Kegan Paul.
Keil, F. (1979). Semantic and Conceptual Development. An Ontological Perspective. Cambridge, MA: Harvard University Press.
MacNamara, J., and G.-J. Boudewijnse. (1995). Brentano's influence on Ehrenfels's theory of perceptual gestalts. Journal for the Theory of Social Behaviour 25:401-418.
Smith, B. (1994). Austrian Philosophy: The Legacy of Franz Brentano. Chicago: Open Court.
Wolenski, J., and P. M. Simons. (1989). De Veritate: Austro-Polish contributions to the theory of truth from Brentano to Tarski. In K. Szaniawski, Ed., The Vienna Circle and the Lvov-Warsaw School. Dordrecht: Kluwer, pp. 391-442 .
Copyright © 1999 Massachusetts Institute of Technology