THE SCIENCE OF LIFE 



special branches of zoology aiid as natural sciences. 

 Hiaman psychology is inseparably coritiected with com- 

 pat-ktive animal psychology, and this again with that of 

 the plants and protists. Philology studies in human 

 speech a complicated iiaturdl phenomenon, which de- 

 pends on the combined action of the brain-cells pi the 

 phronema, the tnuscles of the tongue, and the vocal 

 cords of the larynx, as much as the cry of mammals and 

 the song of birds do. The history of mankind (which 

 we, ih our curious anthropocentric riibod, call the history 

 of the world), and its highest branch, the histoty of 

 civilization i is connected by inodem pre-historic science 

 dlrfectly with the stem-history of the primates arid the 

 other mammals, and indirectly with the phylogeny 

 of the lower vertebrates. Hence, when we consider 

 the subject without prejudice; we do not find a single 

 branch of human science that passes the limits of 

 liatural scienfce (in the broadest sense), any more than 

 we find nature herself to be sujjernatural. 



Just as monism, or naturalism, embraces the totality 

 of science, so on our principles the idea of nature cottl- 

 prises the whole scientifically kndwable world. In the 

 strict inonistic sense of Spinozk the ideas of God and 

 Natute are synonymous for us. Whether there is a 

 realm of the supernatural arid spiritual beyond natUre , 

 we do not khow. All that is said of it in religious myths 

 and legends, or metaphysical speculatioris and dogmas, 

 is mere poetry and an outcome of imagination. The 

 imagination of civilized man is ever seeking to produce 

 unified images in att arid science, and wheri it meets 

 With gaps in these in the associatiori of ideas it en- 

 deavors to fill them with its own creatioris. These 

 cteatioris df the phi-onema with which we fill the gaps in 

 our knowledge are called hypotheses wheri they are iri 

 harmony with the empirically established facts, arid 

 myths when they contradict the facts: this is the case 



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