1509
While they lived , he saw W. " V. Quine and Arthur Prior as his allies , in that they held three truths : that there are no non-existent beings ; that a proposition can occur in discourse without being there asserted ; and that the sense of a term does not depend on the truth of the proposition in which it occurs .
 person: W. " V. Quine; person: Arthur Prior
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 person: W. " V. Quine; person: Arthur Prior