t84 SECTIONAL ADDRESSES 



as well as logically different aspects of recall ? If such recall is image 

 creation under the influence of knowledge that, such changes need not 

 surprise us. The logical analysis of experience involved in conceptual 

 thinking furnishes us with simple ideas of form, colour, size, etc., simple 

 ideas in Locke's ' logical ' meaning. These can enter into conceptual 

 knowledge about objects, but they can also control image constructions 

 built on the lines of perceptual patterns. Such image constructions are 

 not in any literal sense reproductions of a particular sensory organisation 

 and should not be explained by a theory of traces. The attempt to so 

 explain all images entangles those which have their origin in the logically 

 simple, — conceptual knowledge, with those which have their origin in the 

 psychologically simple, — sensory experience. Greatly as memory is con- 

 trolled by concepts, there are the cases which I feel I can only regard as 

 re-creations of the original sensory pattern, genuine memory images. 

 The painting anew on the mind seems directly conditioned by the original 

 sensory experience. It is not an image constructed under the influence 

 of knowledge that. 



Inadequate as this sketch is, I trust it may serve to support the claim 

 that it is important to consider all the constructive hypotheses that are 

 to be found in present-day psychology while continuing patient experi- 

 mental work. We cannot perhaps go forward with the confident belief 

 of the early pioneers that the solution of many problems lies close at hand, 

 but we can possess their spirit of adventure and their enthusiasm for 

 progress. 



When we compare the constructive theories of psychology with those 

 which light up physical science to-day, without envy and without shame 

 we may echo Locke's words in his Epistle to the Reader : ' The common- 

 wealth of learning is not at this time without master-builders, whose 

 mighty designs, in advancing the sciences, will leave lasting monuments 

 to the admiration of posterity : but everyone must not hope to be a Boyle 

 or a Sydenham ; and in an age that produces such masters as the great 

 Huygenius and the incomparable Mr. Newton, with some others of that 

 strain, it is ambition enough to be employed as an under-labourer in 

 clearing the ground a little, and removing some of the rubbish that lies 

 in the way to knowledge.' 



