44788
Avicenna 's consideration of the essence-attributes question may be elucidated in terms of his ontological analysis of the modalities of being ; namely impossibility , contingency , and necessity .
 Avicenna
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Avicenna