Q. I have often disliked authors in the habit of introducing a statement with Firstly or Secondly, and so on. Are there any good rules on this or should it be banished from usage?
A. Merriam-Webster (which Chicago follows) seems just fine with firstly, and secondly. And according to The American Heritage Dictionary, the meaning of firstly is “In the first place; to begin with; first.” So I guess you’ll have to find another reason for disliking authors.