October 20, 1923] 



NA TURE 



57, 



or not, it proves to be singularly in accord with the 

 significance and direction of the new scientific theories. 

 He tells us he is a materialist, but adds that it may 

 be he is the only philosopher who is. All that this 

 seems to mean is that, with Spinoza, he seeks the unity 

 of the world in an objective and deterministic principle 

 rather than, with Leibniz, in a subjective and creative 

 principle. He is no more materialist in the ordinary 

 acceptation of the term than Spinoza is atheist. His 

 theory, however, merits the attention of experi- 

 mentalists. 



His theory is that " existence " is not a datum. 

 We can have no image of it and no idea of it. We 

 accept it with " animal faith." What is " given " to 

 the mind in knowledge is not the existence of objects 

 but their essence. This is true of the mind itself, of 

 the cogito ergo sum, equally with the objects of the 

 physical world. Essence is not a subjective eject : 

 it is objective in the fullest meaning of the term. 

 This rejection of existence as a datum is of special 

 significance in philosophy, for it serves to separate 

 Mr. Santayana from the realists with whom his 

 " materialism " would seem naturally to associate 

 him, from those who, like Prof. Alexander and Prof. 

 Lloyd Morgan, insist on the importance of assuming 

 the existence of the non-mental world, even though 

 it may need to be accepted " with natural piety." 

 But it is of peculiar significance in science ; for if 

 Einstein and the orthodox relativists are right, science 

 has no longer any use whatever for this relic of an older 

 world-view and its pious preservation is a superstition. 

 Santayana's doctrine therefore, which does not reject 

 existence but denies that it is a datum and excludes 

 it from knowledge, is singularly in accordance with 

 the theory that in physical science we are not con- 

 templating absolute existence but co-ordinating 

 phenomena by means of invariants. The " animal 

 faith " which makes us believe the existence of a 

 datum is not the philosophising will to believe or 

 reason for believing : it is the ordinary man's intuition 

 or instinct. 



What then is essence, or rather what are the essences, 

 w'hii h Mr. Suntayana presents as the objective reality 

 of things known ? To the philosopher it is perhaps 

 enough to say that they are the Platonic Ideas inter- 

 I)rti((l in a modem way, a concept which recalls 

 Croco's cTesthctic images, except that essences are not 

 the creations ol a fantasia, or the expressions of 

 intuit idiis, hut passively discerned objects. We are 

 iTiorc intert'sled, however, to know what is their status 

 in .s( icnre. They are, \sc ,ir< told, the indispensable 

 terms in the perception of matters of fact and they 

 render transitive knowledge possible. They are dis- 

 tinguished therefore from " bits of sentience " or pure 

 NO. 2816, VOL. 1 12] 



sense-data, on one hand, by their external reference 

 and from existents or pure existences, on the other 

 hand, by their relatedness. The value of the doctrine 

 to science is then that it takes us behind all such 

 philosophical distinctions as primary and secondary 

 qualities, universal and particular ideas, abstract and 

 concrete terms, giving us at once what is ultimate 

 in the reference to reality. Mr. Santayana takes as 

 an illustration the colour quality " yellow." I may 

 see a buttercup, the intuition is then a sensation ; 

 or I may see it with my eyes shut, it is then an idea 

 or a dream ; or I may see it with my eyes open when 

 there is no buttercup there, then it is hallucination. 

 Whatever be the difference in the mode of apprehending 

 or in the object of reference, the essence yellow is 

 one and identical. 



To see the relevance of this theory to scientific 

 research we have only to recall the endeavour of Mach 

 to construct science out of the relations of sense-data. 

 Mach found he had to fall back on a quite arbitrary 

 hypothesis of parallelism. How different his task 

 might have appeared had he had this conception of 

 essence. His difficulty was to get to existence, and 

 this demands belief. If, on the contrary, with Mr. 

 Santayana, we start from the realm of essence, which 

 demands no belief, we may at once find conclusive 

 reasons for believing that sundry intuitions of parts 

 of it exist in fact. This discrimination of essence 

 brings too a wonderful clearness to the comprehension 

 of the nature of scientific research. All data and 

 descriptions, all terms of human discourse, are essences, 

 inexistent. Existence is an intuition, inexpressible, 

 not knowledge but ignorance, a purely animal faith. 

 The distinction cuts science free from all the per- 

 plexities and antinomies which arise when reality 

 is identified with existence {e.g. the non-existence 

 of the past and future, the inextensiveness of the 

 present). 



Having expounded this important distinction of 

 essence and existence, Mr. Santayana then proceeds, 

 somewhat to our surprise and with at least the appear- 

 ance of complete inconsistency, to select from the 

 essences the philosophical concept of substance and 

 the naturalist concept of matter to be the foundations 

 of his new Jerusalem, a system of philosophy which 

 we are led to expect is shortly to appear. We look 

 forward to it with flccj) interest, for the present intro- 

 duction shows him inspired with a new vision and 

 emboldened to undertake constructive work. His 

 book closes with a critical epitome of the history of 

 modern philosophy in which, except Spinoza, each 

 leadin- philosopher is pelted with cpi-i.iins, and 

 iroui« ally dismissed. 



H. WiLDON CaRR. 



