Drawing on the phenomenological tradition in the philosophy of science and philosophy of nature, Patrick Heelan concludes that perception is a cognitive, world-building act, and is therefore never absolute or finished.

Drawing on the phenomenological tradition in the philosophy of science and philosophy of nature, Patrick Heelan concludes that perception is a cognitive, world-building act, and is therefore never absolute or finished.Drawing on the phenomenological tradition in the philosophy of science and philosophy of nature, Patrick Heelan concludes that perception is a cognitive, world-building act, and is therefore never absolute or finished.

perceptual essences that can be rendered directly manifest in perception with the help of theoretically structured instruments serving as 'readable technologies'. " Scientific knowledge should thus be understood as an extension of "unassisted" perception. A perceptual fact has an outer horizon "which separates it from the ground on which it appears," and an inner horizon "composed of a multiplicity of possible perceptual profiles organized by an invariant essence. " The perceiving subject can "bring forth a representative sample of the profiles in question," occasionally by making use of certain technological processes, which are themselves subject to interpretation in terms of theoretical representations. The theoretical entities described in these representations are not "simply detected thanks to an inferential operation, but rather, they are directly perceived. " It follows from this that the correspondence between the "manifest image" and the "scientific image" is not done one-to-one, but by a "many-to-one or one-to­ many application between contextually defined perceptual objects within contexts that are mutually incompatible but complementary. " This should not, however, be understood as a form of conventionalism, nor as a form of "cultural relativism. " Pre­ comprehension, which guides interpretation imposes strict limits to the descriptive categories which can be used and to the manner in which they can be linked to appropriate empirical objects. The author applies his hermeneutic principles to the study of visual perception. (In fact this question is treated in the first part of the book.

Quantum mechanics has raised in an acute form three problems which go to the heart of man's relationship with nature through experimental science: (r) the public objectivity of science, that is, its value as a universal science for all investigators; (2) the empirical objectivity of scientific objects, that is, man's ability to construct a precise or causal spatio-temporal model of microscopic systems; and finally (3), the formal objectivity of science, that is, its value as an expression of what nature is independently of its being an object of human knowledge. These are three aspects of what is generally called the "crisis of objec­ tivity" or the "crisis of realism" in modern physics. This crisis is. studied in the light of Werner Heisenberg's work. Heisenberg was one of the architects of quantum mechanics, and we have chosen his writings as the principal source-material for this study. Among physicists of the microscopic domain, no one except perhaps Bohr has expressed himself so abundantly and so profoundly on the philosophy of science as Heisenberg. His writings, both technical and non-technical, show an awareness of the mysterious element in scientific knowledge, far from the facile positivism of Bohr and others of his contemporaries. The mystery of human knowledge and human SUbjectivity is for him an abiding source of wonder.

Drawing on the phenomenological tradition in the philosophy of science and philosophy of nature, Patrick Heelan concludes that perception is a cognitive, world-building act, and is therefore never absolute or finished.

Drawing on the phenomenological tradition in the philosophy of science and philosophy of nature, Patrick Heelan concludes that perception is a cognitive, world-building act, and is therefore never absolute or finished.Drawing on the phenomenological tradition in the philosophy of science and philosophy of nature, Patrick Heelan concludes that perception is a cognitive, world-building act, and is therefore never absolute or finished.

perceptual essences that can be rendered directly manifest in perception with the help of theoretically structured instruments serving as 'readable technologies'. " Scientific knowledge should thus be understood as an extension of "unassisted" perception. A perceptual fact has an outer horizon "which separates it from the ground on which it appears," and an inner horizon "composed of a multiplicity of possible perceptual profiles organized by an invariant essence. " The perceiving subject can "bring forth a representative sample of the profiles in question," occasionally by making use of certain technological processes, which are themselves subject to interpretation in terms of theoretical representations. The theoretical entities described in these representations are not "simply detected thanks to an inferential operation, but rather, they are directly perceived. " It follows from this that the correspondence between the "manifest image" and the "scientific image" is not done one-to-one, but by a "many-to-one or one-to­ many application between contextually defined perceptual objects within contexts that are mutually incompatible but complementary. " This should not, however, be understood as a form of conventionalism, nor as a form of "cultural relativism. " Pre­ comprehension, which guides interpretation imposes strict limits to the descriptive categories which can be used and to the manner in which they can be linked to appropriate empirical objects. The author applies his hermeneutic principles to the study of visual perception. (In fact this question is treated in the first part of the book.

Quantum mechanics has raised in an acute form three problems which go to the heart of man's relationship with nature through experimental science: (r) the public objectivity of science, that is, its value as a universal science for all investigators; (2) the empirical objectivity of scientific objects, that is, man's ability to construct a precise or causal spatio-temporal model of microscopic systems; and finally (3), the formal objectivity of science, that is, its value as an expression of what nature is independently of its being an object of human knowledge. These are three aspects of what is generally called the "crisis of objec­ tivity" or the "crisis of realism" in modern physics. This crisis is. studied in the light of Werner Heisenberg's work. Heisenberg was one of the architects of quantum mechanics, and we have chosen his writings as the principal source-material for this study. Among physicists of the microscopic domain, no one except perhaps Bohr has expressed himself so abundantly and so profoundly on the philosophy of science as Heisenberg. His writings, both technical and non-technical, show an awareness of the mysterious element in scientific knowledge, far from the facile positivism of Bohr and others of his contemporaries. The mystery of human knowledge and human SUbjectivity is for him an abiding source of wonder.