62 LESSONS FKOM NATUEE. [CHAP. III. 



thinks has all the serious incongruity of an intense metaphysical 

 dream/ neither affirms the untenable conception of Crude Eealism, 

 nor, like Anti-Realism, draws unthinkable conclusions by suicidal 

 arguments ; but, accepting that which is essential in Crude Realism, 

 and admitting the difficulties which Anti-Realism insists upon, recon 

 ciles matters by a re-interpretation analogous to that which an astro 

 nomer makes of the solar motion. Continuing all along to recognize 

 an objective activity which Crude Realism calls sound, it shows that 

 the sensation is produced by a succession of separate impacts which, if 

 made slowly, may be separately identified, and which will, if progres 

 sively increased in rapidity, produce tones higher and higher in pitch. 

 It shows by other experiments that sounding bodies are in states of 

 vibration, and that the vibrations may be made visible. And it con 

 cludes that the objective activity is not what it subjectively seems, but 

 is proximately interpretable as a succession of aerial waves. Thus 

 Crude Realism is shown that while there unquestionably exists an 

 objective activity corresponding to the sensation known as sound, yet 

 the facts are not explicable on the original supposition that this is like 

 the sensation ; while they are explicable by conceiving it as a rhythmical 

 mechanical action. Eventually this re-interpretation, joined with kin 

 dred re-interpretations of other sensations, comes to be itself further 

 transfigured by analysis of its terms, and re- expression of them in 

 terms of molecular motion ; but however abstract the interpretation 

 ultimately reached, the objective activity continues to be postulated : 

 the primordial judgment of Crude Realism remains unchanged, though 

 it has to change the rest of its judgments.&quot; 



But, in spite of all that Mr. Spencer can urge, it must be 

 itsinsuffi- affirmed, our reason assures us, that the number, 

 figure, and extension of objects are just as certainly 

 real as is the existence of anything beyond consciousness at all. 

 If our conceptions of solidity, figure, and extension are delu 

 sions, scepticism has indeed an impregnable stronghold. But, 

 as we shall shortly see, Mr. Spencer goes so far as to discredit 

 the validity of our perceptions even as to difference itself. 



Mr. Spencer, in his proof-case just quoted, however, bases 

 ea f &quot; his ar g umen t upon an alleged delusion we neces- 

 sound. sar iiy ii e un d er with respect to sound, and this is a 

 matter of great importance in his psychology. 



He says :* &quot;Although the individual sensations and emo 

 tions, real or ideal, of which consciousness is built up, appear 



Psychology. vol. i. p 148, 60. 



