Sentence:  Accordingly we may speak of the Platonism peculiar to Shelley 's poems or the type of Stoicism present in Henley 's `` Invictus '' , and we may find that describing such Platonism or such Stoicism and contrasting each with other <WSD>expressions</WSD> of the same attitude or mode of thought is a difficult and challenging enterprise . 
Meaning of the word marked with <WSD> tags:  the communication (in speech or writing) of your beliefs or opinions