Page:Mind (New Series) Volume 6.djvu/220

IV. ON THE NATURE OF THE NOTION OF EXTERNALITY. 1 BY HOWAED V. KNOX. I. THE present paper has for its object to elucidate the true nature of the notion of externality, and to show that it forms the foundation of the whole of our knowledge. As a background for the views here advocated, I have singled out the formula, Scientific law describes the routine of our perceptions not by reason of any high degree of philo- sophical merit in the work devoted to its exposition and defence, but chiefly 2 because it contains, neatly packed in a small compass, a sweeping denial of every one of the propositions which it is my aim to establish. Before, however, proceeding to attack this formula, it will be ad- visable to give some typical quotations from the book from which it is extracted, so as to be quite sure that we are doing the author, Professor Karl Pearson, no injustice : " If the reader once grasps the characteristics of this law of Newton's [the law of gravitation] he will understand the nature of all scientific law. . . . Such laws simply describe, they never explain the routine of our perceptions, the sense- impressions we project into an ' outside world '." 3 " While in the nature of perceptions themselves there appears nothing tending to enforce an order, D, E, F, G, rather 1 The views here advocated are in the main identical with those set forth by Mr. Stout in his article on " The Genesis of the Cognition of Physical Reality " (MiND, xv., No. 57) ; but the general standpoint is somewhat different. 2 Another reason that has helped to determine my choice is that Pro- fessor Karl Pearson, by his mode of treatment, is apt to bring into dis- credit the very cause which, at bottom, he is seeking to defend, and in maintaining which I am entirely at one with him the cause, namely, of science versus (so-called) constructive metaphysics. 3 The Grammar of Science, p. 119.