[170] The importance of this consideration about the “attention” that is (as a matter of fact and a matter of necessity) involved in all “perception,” cannot possibly be exaggerated. We perceive in childhood and throughout life in the main what interests us, and what affects our total and organic activity. It is, that is to say, our motor activity, and its direction, that determine what we see and perceive and experience. And in the higher reaches of our life, on the levels of art and religion and philosophy, this determining power becomes what we call our reason and our will and our selective attention. Perception, in other words, is a kind of selective activity, involving what we call impulse and effort and will. Modern philosophy has forgotten this in its treatment of our supposed perception of the world, taking this to be something _given_ instead of something that is _constructed_ by our activity. Hence its long struggle to overcome both the apparent materialism of the world of the senses, and the gap, or hiatus, that has been created by Rationalism between the world as we think it, and the world as it really is. [171] _E.g._ Professor Bosanquet, in his 1908 inaugural lecture at St. Andrews upon _The Practical Value of Moral Philosophy_. “Theory does indeed belong to Practice. _It is a form of conation_” (p. 9). It “should no doubt be understood as Theoria, or _the entire unimpeded life of the soul_” (p. 11; italics mine). [172] This is surely the teaching of the new physics in respect of the radio-active view of matter. I take up this point again in the Bergson chapter. [173] See p. 238. [174] See p. 143 or p. 229 (note). [175] See p. 34 in Chapter II. in reference to the idea of M. Blondel. [176] See p. 147 and p. 265. [177] See p. 65, note 3. [178] See p. 192, note 3. [179] Needham, _General Biology_, 1911. For the mention of this book as a reliable recent manual I am indebted to my colleague, Professor Willey of McGill University. [180] Marett, _Anthropology_, p. 155. [181] Cf. _supra_, p. 101. [182] So much may, I suppose, be inferred from the contentions (explicit and implicit) of all biologists and evolutionists. Human life they all seem to regard as a kind of continuity or development of the life of universal nature, whether their theory of the origin of life be that of (1) “spontaneous generation,” (2) “cosmozoa” (germs capable of life scattered throughout space), (3) “Preyer’s theory of the continuity of life,” (4) “Pflüger’s theory of the chemical characteristics of proteid,” or (5) the conclusion of Verworn himself, “that existing organisms are derived in uninterrupted descent from the first living substance that originated from lifeless substance” (_General Physiology_, p. 315). [183] _Creative Evolution_, pp. 245–5.