Hunter Baker's thoughts on Dashiell Hammett, posted earlier today, are interesting and well expressed. Hammett's Continental Op is an excellent character that brought something fairly new to the genre, a realistic sense of the largely mundane and tawdry nature of the private-investigation racket. (But we should not pretend that even this was entirely original—right after the Sherlock Holmes stories became popular, British author Arthur Morrison explored this mundaneness of detection in his excellent Martin Hewitt stories, as did other authors of the prewar period.) The Op stories are largely believable and have a strong narrative drive. In addition, the characters of Sam Spade and Nick and Nora Charles are highly distinctive and memorable. The latter two are quite likeable, as well. The Thin Man is in fact my favorite among Hammett's books.
The Maltese Falcon is his best, in my view. It is a powerful story driven by the difficult moral choices the protagonist, Sam Spade, has to make as he pursues his partner's killer. Spade himself is far from perfect (though by no means a monster), which makes the twists and turns of his quest more interesting, as the reader is continually invited to guess at his true motives. In this way, the book is as much of a game between author and reader as are the most artificial of puzzle mysteries. Nonetheless, the events of the book always seem real, and Hammett's greatest authorial asset may well be his ability to convince the reader that his highly melodramatic romances are in fact entirely plausible and true to life. They are, of course, nothing of the sort, and that is what engages our imagination so strongly. They are romances we can believe—the most enticing romances of all.
On the deficit side, however, I find it rather annoying when people claim that Hammett originated the hardboiled genre. That honor belongs to Carrol John Daly, whose "Three Gun Terry" appeared in Black Mask on May 15, 1923, five months before the same magazine published Hammett's first Op story. Hammett has been more widely acknowledged as an influence on the many writers who followed in the hardboiled style, but Daly deserves credit for getting there first, and what is more, I think he deserves more credit as an influence that most critics have been willing to allot to him. Daly came up with an essential element of the hardboiled detective tale, which is the translation of the Western story into modern, urban situations. It was an ingenious idea, and it is surely the real foundation of the hardboiled form. In addition, Daly brought in the emphasis on political corruption as a major theme right from the start, another important element of the form.
Hammett, however, was a much more convincing storyteller. Daly's tales are frankly fantastic and just good, crazy fun. As greatly entertaining as they are (and they really are a treat), they do not involve the kinds of moral dilemmas Hammett's stories did. Race Williams, Satan Hall, Vee Brown, and Daly's other detectives are right, and whatever they do is therefore right. They have no doubts about that, and neither does the author, and neither does the reader. And that can be fun, and even sometimes rather inspiring.
It can never be very intellectually or morally insightful, however. That was the essential element Hammett added to the genre, and it is what makes his tales occasionally reach levels of real drama and insight.