This collection of essays is Gould's last as an author but my first as a reader of him. They are somewhat eclectic, though grouped according to theme and overall evolution and scientific method crop up the most often. Technically, the approach is less diverse, with an opening starting with some personal or topical (at the time of writing) anecdote leading into a more general discussion of a Big Idea. This is somewhat irritating to me, because it reminds me of Radio 4's Thought for the Day, in which a news story is used to lead into some crass attempt to foist religion on to me.
The main body of each essay is well argued and clearly explained and demonstrates that Gould had not only a thorough understanding of his subject but the history of it, too. I learned much about modern ideas about evolution and found his remarks on scientific method interesting and worthwhile. It is also clear that he found an ocean of incomprehension of evolution around him - which he tried to mop up with his books, knowing that they could hardly even have a measurable effect.
I am left, however, with an even stronger desire for a book (preferable by Gould or Eldredge) in which a coherent description of evolution and all scales of operation is given. If anyone knows of one such, please mention it!