46 INTEKNATIONAL LANGUAGE AND SCIENCE 



words from the other. There is only a very slight difference of 

 meaningbetween a katolika skeptiko and a skeptikakatoliko, the 

 substantive indicating in each case the primary and funda- 

 mental idea to which the other is superadded. 



This brings us to the enunciation of the principle of 

 reversibility, which maybe formulated as follows: "Every 

 derivation must be reversible ; that is to say, if one passes 

 from one word to another of the same family in virtue of a 

 certain rule, one must be able to pass inversely from the 

 second to the first in virtue of a rule which is exactly the 

 inverse of the preceding." That is an evident corollary of 

 the principle of uniqueness, for otherwise one would be led 

 to give two meanings to the same word. Let us suppose, for 

 example, that from the noun krono, = a crown, one imagines 

 it possible to derive directly (as is the case in certain 

 languages) the verb kronar = to crown. From this verb 

 one could deduce inversely in virtue of the general rule the 

 substantive krono = coronation, so that the same word krono 

 would then mean both crown and coronation. That would 

 be, however, a logical error inadmissible in the international 

 language, however numerous may be the examples of it which 

 occur in living languages. On the contrary, thanks to the 

 principle of reversibility, one can proceed from any word 

 whatsoever of a family and arrive at any other word of the 

 same family, or return to the initial word, in an absolutely 

 unique manner, whereas if one did not observe this principle 

 one would inevitably obtain two meanings for the same 

 word. 



The principle of reversibility fixes the rules of direct 

 derivation for the cases which are the converse of those 

 we have studied. Just as the substantive directly derived 

 from a verb denotes the state or action expressed by this 

 verb (or, more strictly, by its root), so a verb can be derived 

 directly from a substantive only if the latter expresses an 

 action or a state. For example, paco = peace ; can one 



