Multidimensional scaling of subjective color differences has shown that color stimuli are located on a hypersphere in four-dimensional space. The semantic space of color names is isomorphic with perceptual color space. A spherical four-dimensional space revealed in monkeys and fish suggests the primacy of common neuronal basis.

According to the received opinion there is a theoretical incompatibility between Herbert Hart's The Concept of Law and Alf Ross's On Law and Justice, and, according to the received opinion, it stems above all from Hart's emphasis on the internal point of view. The present paper argues that this reading is mistaken. The Concept of Law does not go beyond On Law and Justice in so far as both present arguments to the effect that law is based on a shared (...) understanding between participants in a project perceived by every participant to be a project in common. The paper demonstrates that there are substantive parallels between Hart's combination of “acceptance” or “acknowledgement” and a “critical reflective attitude” and Ross's combination of “motivation” or “feeling” and a “coherent whole of meaning and motivation.” The main conclusion is that the views of norms and normativity put forward in The Concept of Law and On Law and Justice are very close in essential respects, and, more specifically, that the two works are at root identical in their representation of the basis of normativity in reality. (shrink)

The perceptual circularity demonstrated by R. Shepard with respect to hue turns out to be a sphericity of color perception based on color excitation vectors of neuronal level. The spherical color model implicitly contains information concerning generalization under color learning. Subjective color differences are “computed” in neuronal nets being represented by amplitudes of evoked potentials triggered by color change. [Shepard].

Edelman suggests that any shape is encoded by an excitation vector with components corresponding to excitations of corresponding neuronal modules. This results in discrimination of stimuli in a shape space of low dimensionality. Similar vector encoding is present in color vision. Red-green, blue-yellow, bright and dark neurons are modules that represent a number of different color stimuli in color space of low dimensionality. Vector encoding allows effective computation of color differences and color similarities. Such a neuronal vector-encoding approach has also (...) been applied to the perception of visual movement, line orientation, and stereopsis. (shrink)