Sure, it is important to be precise, and to use the right terms, and ideally your writing should reflect a level of formality, BUT… you are not doing yourself any favours by hitting the Thesaurus button in your word-processing software for every other word. On the contrary, chances are that will make your writing worse! Because at the end of the day, you are trying to make a point and not to craft an incomprehensible word painting (possibly with words you don’t fully understand, but that sound good to you). Instead of focusing on making your argument sound impressive, focus on making an impressive argument in plain English.
Stephen King said that if you need a Thesaurus to find a word, it isn’t the right word…
Writing by Pictures 