Sentence:  Pessimists, no more than poets, love each other, and even when they work together it is one thing to <WSD>pessimise</WSD> congenially with an ancient and tried associate who is also a butt, and another to be <WSD>pessimised</WSD> over by an inexperienced junior, even though the latter's college career may have included more exhibitions—nay, even pot-huntings—than one's own. 
Meaning of the word marked with <WSD> tags:  To think like a pessimist; to believe the worst.