Cosmology

COSMOLOGY. - From the Greek κόσμος (world) and λόγος (discourse), it is the part of natural philosophy that studies corporeal being in general, and the universe as a whole. As the title of a philosophical treatise the term appears for the first time in C. Wolff (C. generalis, Frankfurt 1731) and was subsequently adopted, particularly by the Neo-Scholastics, either simply in replacement of the traditional term "physica", or, more often, to designate the general part of "physica".

I. HISTORY

In the history of Western thought the philosophy of nature arises within the framework of a process in which the vision of the world as φύσις is acquired, that is, as an autonomous reality, moved and governed by immanent forces according to definable laws. Among the first Ionian philosophers the new conception appears linked with a unitary view of the entire cosmos which, in the face of the multiformity and inconstancy of things, demanded the distinction between the variable forms and the single and imperishable ground of reality. The determination of this ground became the first problem of cosmology. With the Pythagoreans' discovery of the normative role of numbers in natural phenomena, a new and important motif was introduced into speculation, one that contributed to the orientation of thought toward a pluralistic and atomistic cosmology. The Eleatic school represents in part a reaction against this Pythagorean tendency: the basis of its doctrine is a dialectic which for the first time develops the problems of becoming, of being and of its determinations from an ontological point of view. The paradoxical consequences to which Eleatic monism came led to the two attempts of Empedocles and Anaxagoras to take up cosmological questions on a pluralistic basis. Eleatic and Pythagorean motifs are also combined in the atomistic system of Democritus.

In Plato's thought cosmology does not establish itself as an autonomous science. Everything knowable in empirical things comes to them from the ideas and from mathematical values. Scientific propositions about things are therefore possible only at the level of a mathematized physics. In Plato's philosophy, however, this mathematism acquires a wholly original meaning: numbers and figures are the norms of a preparatory order, intermediate between the ideas and sensible things. Above the mathematical order, then, stands the order of essences, the immediate expression of the dialectical relations among the ideas themselves. The modifications that Platonic tendencies undergo in Aristotle are governed principally by the idea of the ontological primacy of concrete being. In the realm of essences this primacy corresponds to that of the εἶδος ἔσχατον, which stands to generic essences in the relation of act and potency. Thus Plato's descending dialectic falls away, and with it the a priori conception of science. Among the four kinds of causes, final causes hold the first place. The teleological order that orients all beings toward the supreme good is limited only on the part of prime matter. In treating the intrinsic principles of bodies Aristotle develops his hylomorphic doctrine (v. ILEMORFISMO).

Christianity, with the doctrine of a transcendent God and of creation, introduced a view of the universe that Greek and Hellenistic philosophy, despite notable approximations, had not attained. In the development of this new conception the writers of the patristic age made extensive use of the doctrines then current, especially those of the Stoic and Platonic schools. An occasion to treat cosmological questions more fully presented itself to them in the commentaries on Genesis; the commentaries on the Hexaemeron become, from Theophilus of Antioch and Origen onward, a typical literary form in which the Fathers' thoughts on the universe find their expression.

The cosmology of Scholasticism took on a rich and multiform development. The superiority of Aristotelian physics assured it, from the middle of the 12th century onward, an important influence even among Scholastics of Augustinian (school of St. Bonaventure) and Neoplatonic (Ripellino and Hugh of Strasbourg, Vitello) orientation. Medieval cosmology reached its culmination with the reconstruction of Aristotelian physics in the work of St. Albert and St. Thomas. The incorporation of Aristotelian doctrine into the great philosophical-theological syntheses demanded certain corrections and complements, which are of importance also for the deeper direction of cosmological speculation. Thus divine exemplarism is, among the medievals, a common doctrine, and chance is subordinated to God's providence; furthermore, the metaphysics of cosmic causality is deepened and emended.

Modern cosmological systems were immediately prepared by a current, alive especially in Italy and Germany, in which the passage was accomplished from the inner experience of late medieval mysticism to an enthusiastic experience of the universe, more or less close to pantheism. The principal inspirer of this current is N. Cusanus, its most influential representatives G. Bruno and Paracelsus. The natural sciences constituted another factor of the greatest importance. The first fruit of the new scientific movement was modern mechanics (G. Galilei, C. Huygens, I. Newton), which acquired an ever broader influence and led to the collapse of the physics of sensible qualities. The tendencies at work in the new physics find a first expression, inspired by a mathematical rationalism, in the mechanistic cosmology of Descartes.

In Kantian criticism a distinction in principle is placed in the foreground between the critically securable sciences of the objects of experience and metaphysics. Theoretical knowledge of nature is in substance identified with Newtonian physics. By reason of the limited scope of this knowledge, Kant can avoid its dogmatico-physicalistic consequences.

For the history of cosmology from the end of Romanticism onward, the orientation of all the natural sciences toward the scientific ideal of physics was of decisive importance. The debate over the true meaning and scope of the scientific image of the world, constructed under the methodological guidance of physics, characterizes the following period, otherwise little homogeneous. The dogmatic acceptance of scientific concepts led to a group of doctrines (materialism, energetism, evolutionism) lacking the necessary philosophical depth. The philosophers of the positivist group (A. Comte, E. Mach) subject scientific methods to a critique that is ordinarily founded on the presuppositions of a radical sensistic empiricism. Other philosophers, by contrast (E. v. Hartmann, H. Driesch), defend the right and the necessity of a natural philosophy whose task they see in the extension and deepening of the image of the world traced by the empirical sciences, so that it may satisfy the demands of a total causal and final comprehension.

For the continuators of the Scholastic tradition, in the face of the profound differences between Aristotelian physics and the results of the natural sciences, there arose the task of bringing out the properly philosophical content of the traditional doctrine and of demonstrating the possibility and necessity of a cosmological speculation prior to and beyond experimental inquiry. The Neoscholastics were able firmly to demonstrate that the essential theses of their cosmology are founded upon general philosophical principles and upon the most universal and fundamental data of experience.

II. PROBLEMS

The deepest divergences that have appeared in the history of cosmology derive from the diversity of metaphysical presuppositions. The decision of questions such as idealism or realism, the relations between cosmic being and absolute being, monism or pluralism, does not belong to natural philosophy, but to metaphysics. However, even after the elimination of these problems from cosmology, there remains a group of questions which, although ordinarily discussed in treatises of natural philosophy, are, strictly speaking, metaphysical. The questions concerning the temporal existence of corporeal things, that is, their becoming and perishing as substances and their accidental mutability, the composibility of the autonomy of individual beings with dependence on others and of substantial unity with the multiplicity of integral parts, are the most important of this group. The Aristotelian tradition seeks the solution of these on the basis of the metaphysical theory of potency and act and of hylomorphism, which is the application of that theory to the constitution of bodies. The problems of transeunt causality receive their clarification principally from the doctrine of the identity between the act of action and of "passio."

A second group of problems centers around the question of the physical essence of bodies. It concerns the determination of the essential and fundamental properties of bodies in general and of the order and manner according to which the other corporeal determinations result from them. In these questions cosmology finds itself in closer contact with experimental investigation, as is also shown by some of the answers, intimately connected with physical theories (mechanicism, the recent dynamism based on the physics of the electro-magnetic field). The Scholastics consider quantity as the primary property of bodies, immediately connected with their materiality. The difficulties concerning continuous extension, which have formed one of the most important motives for the elaboration of the various dynamic theories, are resolved with the doctrine of the actual unity of the continuum (v.), which is at the same time a potential multiplicity. Against mechanicism, however, the Scholastics reject the denial of the qualitative properties and of the intrinsic mutability of bodies, insisting especially on the existence of operative powers, required by the causal explanation of any natural mutation. Also in the question of the nature of spatial relations the Scholastic doctrine departs from the mechanico-dynamic conceptions by affirming space as "ens rationis" which has its foundation in the real extension of bodies and in the dimensional relations that derive from it. Connected with that of space is the question of time, resolved on the basis of the Aristotelian principle that gives to the concept of time a real foundation in successive motion.

To the questions relative to the generic properties of bodies is connected the question of the principles of their differentiations. Here too the Neo-Scholastics consider the explanations of the atomistic type, which derive the diversities in the corporeal world from non-specific differences, insufficient to account especially for the chemical diversities of bodies; ordinarily they explain the results of chemical and physical analysis with the theory of the virtual presence of the substantial forms of the components in the specific actual unity of the compound (v.). In the question of the order of essential structures the Aristotelian school defends in corporeal entities a hierarchy of forms, in which the higher forms integrate in themselves the perfections of the lower ones.

A last group of questions concerns the world as a whole. To it belong in the first place the questions relative to the order of the universe. Against the doctrines that derive the structure and development of the universe from chance, or from cosmic forces transcending individual beings, the Scholastic tradition defends a teleological tendency of all cosmic beings toward the constitution and conservation of a harmoniously ordered universe; the lower substances are destined for the use of higher beings; the whole cosmos is ordered to attain, in the use and knowledge of it by man, its highest meaning in relation to the immanent final order of the universe. The deficiencies of the cosmic order and the apparent dysteleologies pose the problem of cosmodicy: Aristotelian philosophy seeks its solution principally on the basis of the doctrine that the rational law of forms does not reach the complete subordination of the indeterminate potentiality of prime matter. The questions concerning the direction and the reasons of cosmic development have, thanks to the investigations of the sciences, received a more determinate content. Especially in the face of the history of vital forms there arises the question in what manner and to what extent the development of the universe is determined by the causal factors of the cosmos itself (v. EVOLUZIONISMO).

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