THE ORIGIN OF THE HUMAN SOUL 247 



passions (which are functions of the organic or sensual appe- 

 tite), and not of rational concepts. In the third place, it is 

 indicative, that is, it merely signalizes a determinate emotional 

 state, as a thermometer indicates the temperature, or a 

 barometer the atmospheric pressure. It is not, therefore, de- 

 scriptive, in the sense of being selected and arranged in syn- 

 tactic sequence for the express purpose of making others 

 realize one's own experiences. The rational language of man, 

 on the contrary, is not emotional. Only a negligible portion 

 of the human vocabulary is made up of emotional interjections. 

 It consists, for the most part, of sounds descriptive of thought, 

 to express which an elaborate system of vowels and conso- 

 nants are discriminated and articulated on the basis of social 

 agreement, the result being a conventional vocal code invented 

 and used for the express purpose of conveying, not emotions 

 or imagery, but general and abstract concepts. 



§ 5. The True Significance of Instinct 



A third class of facts commonly cited as evidence of bestial 

 intelligence are the remarkable phenomena of instinct.^ The 

 beaver acts as though it were acquainted with the principles 

 of hydraulics and engineering, when it maintains the water at 

 the height requisite to submerge the entrance to its dwelling by 

 building a dam of mud, logs, and sticks across the stream at 

 a point below the site of its habitation. The predatory wasp 

 Pomjpilius is endowed with surgical art, that suggests a 

 knowledge of anatomy, inasmuch as it first disarms and after- 

 wards paralyzes its formidable prey, the Lycosa or black 

 Tarantula. Another predatory wasp, the Stizus ruficomiSf 

 disables Mantids in a similar fashion. One of the American 



'J. Henri Fabre and Erich Wasmann, S.J., have formulated very 

 sound and critical views on the subject of instinct. The works of 

 these authors are now available in English. (C/. de Mattos' translation 

 of the Souvenirs etymologiques : "The Mason Bees," Ch. VII; **The 

 Bramble Bees," Ch. VI; "The Hunting Wasps," Chs. IX, X, XX; cf. 

 also Wasmann's Instinct and Intelligence, and Psychology of Ants and 

 of Higher Animals, Engl, translation by Gummersbach.) 



