t 



1 8 POPULAR SCIENCE MONTHLY. 



matter, by which alone the same can act, that is, the living plasma. 

 The soul is actual; it is the sum of the physiological functions of the 

 material organs. The human soul is a collective term for a sum of 

 brain functions, and these are like all other life processes conditioned 

 by physical and chemical processes, and hence like all the rest subject 

 to the law of substance. 



Let us now see what has become of Haeckel's original monistic 

 theory. According to the original proposition there is one underlying 

 substance of which matter and energy are the attributes. What this 

 substance is, no one knows; perhaps it does not exist at all; perhaps 

 it is force ; perhaps prothyl, perhaps ether. But never mind that. We 

 have the two aspects of it in extended space-filling stuff, and the sen- 

 tient energy. All of a sudden this unitary substance begins to turn 

 itself into a plurality of atoms or pyknatoms; the one becomes the 

 many, monism becomes pluralism. How is this to be explained? It 

 is all very simple to Haeckel. Atoms have souls, feelings and desires, 

 and these properties cause the atoms to contract. 



Without the assumption of an atom- soul, says Haeckel in another place,* 

 the most common and most general phenomena of chemistry are inexplicable. 

 Pleasure and pain, desire and aversion, attraction and repulsion must belong 

 to all mass-atoms; for the movements of the atoms which must take place in 

 the formation and separation of every chemical combination can be explained 

 only if we ascribe to them sensation and will (Empfindung und Wille) . 



That is, the physical pluralism is explained by assuming a pluralism of 

 forces. But why the unitary substance should desire to differentiate 

 we are not told. But ignoring this difficulty, we note that these atom- 

 souls or soul-atoms, these properties of sensation and will, cause the 

 atoms to contract, and hence cause motion. That is, the attribute of 

 energy, sentient force, mind, thought, or whatever else Haeckel may 

 choose to call it, causes motion, makes matter move, produces a change 

 in the other attribute. Almost in the same breath we are told that there 

 is no form of energy which is not caused by movements of matter, f 

 That is, the energy causes the movement, and the motion causes the 

 energy. These statements not only contradict each other, but are out 

 of harmony with the original standpoint of Haeckel, according to 

 which mind and matter are attributes of an underlying substance, 

 dependent upon this and not upon each other. 



Haeckel's pure monism, we see, seems to turn into the much- 

 despised dualism. But this is only a passing stage in the philosophical 

 drama. We are hurried on rapidly to the denouement in the chapters 

 on the soul, where the so-called psychical processes become the func- 

 tions of physiological processes, of physical and chemical changes. We 



* ' Perigenesis der Plastidule,' pp. 38f. 

 t ' Weltraethsel,' pp. 255f. 



