Summary Franz Brentano, 1838–1917, introduced the intriguing concept of “plerosis” in order to account for aspects of the continuum that were “explained” by formal mathematics in ways that he considered absurd from the perspective of intuition, especially visual awareness and imagery. In doing this, he pointed in directions later developed by the Dutch mathematician Luitzen Brouwer. Brentano’s notion of plerosis involves distinct though coincident points, which one might call “atomic entities with parts”. This notion fits the modern concepts of “receptive (...) field” in neurophysiology, “perceptive field” in psychology and “differential operator” in the formal theory of scale space. We identify Brentano’s boundary points as the primordial atomic Gestalts of visual imagery. The concept deserves to play a key role in Gestalt theory. (shrink)

The apparent dichotomy between qualitative versus quantitative dimensions in science intersects with the domain of several disciplines, as well as different research fields within one and the same discipline. The perception of qualitative as “poor quantitative,” however, is methodologically unsustainable, because there are perfectly rigorous ways to conduct qualitative research. A somehow different question is whether a science of qualities per se is possible: that is, whether a science of appearances can be devised, what its observables are, and its methodological (...) implications. The article deals with this last issue, and especially from the point of view of experimental phenomenology. The weakness of the current approach to perception is discussed, and an alternative view that goes beyond veridicalism is presented. The analysis tackles crucial issues such as color and spatial appearances, the qualitative dimension of perceived depth, and the role of visual meaningful gestalten as information tools for the survival of living beings in the environment. If developed, a science of the qualitative dimensions of appearances may contribute to revising the ecological theory of perception by making its natural semantics more explicit. (shrink)

Experimental phenomenology is the study of appearances in subjective awareness. Its methods and results challenge quite a few aspects of the current debate on consciousness. A robust theoretical framework for understanding consciousness is pending: current empirical research waves on what a phenomenon of consciousness properly is, not least because the question is still open on the observables to be measured and how to measure them. I shall present the basics of experimental phenomenology and discuss the current development of experimental phenomenology, (...) its main features, and the many misunderstandings that have obstructed a fair understanding and evaluation of its otherwise enlightening outcomes. (shrink)

Space—an essential dimension of our life—is analyzable from different viewpoints, which often gives rise to contrasting conceptualizations. Perceptual analyses shed light on the intrinsic anisotropy and deformations of perceived space, raising the issue of which geometry may be able to represent perceptual space. Pictorial drawings and painting have been relevant sources of information about the nature of living and perceived space. Although the geometry of perceptual space is still in its infancy, contributions are beginning to appear. This special issue contributes (...) to the development of the geometry of perceptual space. (shrink)