TRUTH 



tion ; both of these are in opposition to reason, since they 

 demand a behef in miracles. 



"All natural science is philosophy, and all true philos- 

 ophy is natural science. All true science is natural phil- 

 osophy.' ' I expressed in these words the general result of 

 my monistic studies in 1866 (in the twenty-seventh chap- 

 ter of my Generelle Morphologie). I then laid it down as 

 the fundamental principle of the monistic system that 

 the unity of nature and the unity of science follow abso- 

 lutely from any connected study of modem philosophic 

 science, and I expressed my conviction in these terms: 

 "All human science is knowledge based on experience, 

 or empirical philosophy; or, if the title be preferred, 

 philosophic empiricism. Thoughtful experience, or 

 thought based on experience, is the only way and 

 method to be followed in the search for truth." I 

 endeavored to estabUsh these theses conclusively in the 

 first book of the Generelle Morphologie, which contains 

 (p. 108) a critical and methodological introduction to this 

 science. Not only are those methods considered ' ' which 

 must necessarily supplement each other" (I. Empiricism 

 and Philosophy; II. Analysis and Synthesis; III. In- 

 duction and Deduction), but also those "which neces- 

 sarily exclude each other" (IV. Dogmatism and Criti- 

 cism; V. Teleology and Causality, or Vitalism and Me- 

 chanicism; VI. Dualism and Monism). The monistic 

 principles which I developed there thirty-eight years 

 ago have only been confirmed by my subsequent labors, 

 and so I may refer the interested reader to that work. 

 The Riddle of the Universe is in the main an attempt to 

 introduce to the general reader in a convenient form the 

 chief points of the monistic system I established. How- 

 ever, the opposition which has been aroused by the 

 general philosophic observations of the Riddle compels 

 me to give a further explanation of the chief features 

 of my theory of knowledge. 



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