Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. This requires not that the writer make all his sentences short, or that he avoid all detail and treat his subjects only in outline, but that every word tell.
There’s an amazing thing that happens when you start using the right dictionary. Knowing that it’s there for you, you start looking up more words, including words you already know. And you develop an affection for even those, the plainest most everyday words, because you see them treated with the same respect awarded to the rare ones, the high-sounding ones.
Which is to say you get a feeling about English that Calvin once got with his pet tiger on a day of fresh-fallen snow: “It’s a magical world, Hobbes. Let’s go exploring!”