In the same vein, if it helps your reader understand your point, use the most precise word that means what you mean to say and is easily understandable. Synony

In the same vein, if it helps your reader understand your point, use the most precise word that means what you mean to say and is easily understandable. Synonyms have differences, and the additional depth is helpful in many circumstances - this is the whole point of scientific 'jargon'. However, I don't think that conflicts with pg's overall point, perhaps just nitpicking his example. I do think that 'mercurial' has its uses.