Introduction to the Philosophy of St. Thomas Aquinas
Of Aristotle's philosophy none was more promptly challenged by the moderns than his physics or philosophy of nature. Witness, among others, the criticism leveled against it by Descartes. Nevertheless, Aristotle's physical doctrine is an essential part of his philosophy, and the student of Aristotelian thought cannot afford to neglect it. Not a few Scholastic authors have tried to give it a more modern twist, how successfully is not now the point. We have chosen to adhere more closely to the analysis and reasoning which Aristotle himself presents in his text. At the same time we have made note, as occasion called, of certain aspects that could stand improvement, provided this be done discreetly, so as not to undermine the very foundations of this time-honored philosophical edifice. Both history and philosophy would, we believe, be bettered served by such prudent handling. At all events, this volume is not an attempt to modernize the traditional philosophy of nature, to bring it up to date, as it were. A modern philosophy of nature according to the mind of Aristotle presumedly waits to be written, but it was not what the author set himself.
A second point bears on terminology and the content of natural philosophy. Through the influence of Christian Wolff (1679-1754) it became the fashion to speak of "cosmology" instead of "philosophy of nature" or "natural philosophy." Wolff also popularized the word "psychology." Whether or not one adopts this terminology may be a matter of taste. More important, however, is the sharp cleavage which then came to be made between one and the other, between cosmology and psychology. It is not so in Aristotle; psychology is the orderly continuation of natural philosophy or, if one chooses, of cosmology. Again, in their cosmologies some modern authors include the general study of life. We believe the better place for this is at the beginning of psychology. To put the preliminary notions of life into cosmology leads to excessive isolation of another kind. In the study of man, that is, it has the effect of stranding his mental self from his physiological self. This, too, ill comports with Aristotle's view in the matter.
Lastly, many of the older and still available textbooks on Aristotle's natural philosophy display a great concern to harmonize the scientific notions of their day with Aristotle's thought. Thus, these books were wedded to the fate of the science they sought to "Aristotelize"; they are out of date. Partly on this account we have limited the present study to what is more basic, hence further removed from the swings of fortunes that modern science cannot escape. This has made for a more abbreviated volume than others in this series on the philosophy of St. Thomas. As an introduction to the traditional philosophy of nature, however, which is its scope and purpose, it is meant to be complete and should be adequate.