THE IMMORTALITY OF THE SOUL. 193 



dogma to a critical examination, and to prove its 

 untenability in the light of the empirical data of 

 modern biology. 



In order to have a short and convenient expression 

 for the two opposed opinions on the question, we shall 

 call the belief in man's personal immortality " atha- 

 natism " (from athanes or athanatos = immortal). On 

 the other hand, we give the name of " thanatism " 

 (from ihanatos— death) to the opinion which holds 

 that at a man's death not only all the other physio- 

 logical functions are arrested, but his " soul " also 

 disappears — that is, that sum of cerebral functions 

 which psychic dualism regards as a peculiar entity, 

 independent of the other vital processes in the living 

 body. 



In approaching this physiological problem of death 

 we must point out the individual character of this 

 organic phenomenon. By death we understand simply 

 the definitive cessation of the vital activity of the 

 individual organism, no matter to which category or 

 stage of individuality the organism in question belongs. 

 Man is dead when his own personality ceases to exist, 

 whether he has left offspring that may continue to 

 propagate for many generations or not. In a certain 

 sense we often say that the minds of great men 

 (in a dynasty of eminent rulers, for instance, or 

 a family of talented artists) live for many generations ; 

 and in the same way we speak of the ' ' soul " of a 

 noble woman living in her children and children's 

 children. But in these cases we are dealing with 

 intricate phenomena of heredity, in which a micro- 

 scopic cell (the sperm-cell of the father or the egg-cell 

 of the mother) transmits certain features to offspring. 

 The particular personalities who produce those sexual 



