Okay, I finally got a copy of the Patricia Cornwell book (Portrait of a Killer: Jack the Ripper, Case Closed). I already knew about some of the research that she’s done on Walter Sickert, her suspect. So I expected a fairly straightforward, logical approach in her presentation of the evidence.

I think my first hint that this may not be the case occurred when I was flipping through the book, looking at the photos. In the very first section of photos, I came across a picture of Sickert’s first wife. But how is she captioned? As “the first wife of Walter Sickert, Ripper suspect”? (which would be the most intellectually honest way to do it). No, she’s captioned: “the daughter of a famous politician and the first wife of Jack the Ripper.”

Now, I don’t know about you, but when I read an argument (i.e. a piece of writing attempting to convince the reader of something), I want a fact-based, logical presentation of the case. Rhetorical bells and whistles are fine, but I don’t want to be manipulated into accepting an argument by rhetoric or repetition, and I do want the writer to anticipate potential objections to her case and refute them by using some type of evidence. This is what I taught my college students when I taught argumentative strategy at places like UCLA and Fullerton College. And it’s certainly what I expect from an argument written by a professional!

Instead, Cornwell loads her argument here, without having to produce evidence. She can just use a caption to make her argument for her, with no qualifier (like “first wife of the man most likely to have been Jack the Ripper”), and no indication of an opportunity for rebuttal. The caption to this photo “begs the question”–i.e. it assumes the very thing that it’s Cornwell’s job to prove.

Now, I’m not going to accuse Patricia Cornwell of sloppiness or dishonesty, but it is true that sloppy or intellectually dishonest writers try all the time to sway readers through these means. So today’s blog is really a lesson on the sorts of things to look out for when a writer crosses the line from legitimate argument into manipulation. And captioning a photo “first wife of Jack the Ripper” is nothing if not manipulative. I doing so, Cornwell is indicating her own certainty that Sickert is Jack the Ripper, and by that means is rhetorically bullying you to buy into her case.

Well, naturally, we assume that Cornwell will ultimately produce evidence of Sickert’s possible guilt in the actual content of her book, and eventually she does. So how is her presentation there? Is it tight? Is it sloppy? Does she leave a lot of hanging threads? Does she tie up her case nicely, by anticipating potential reader objections and refuting them?

Well, here’s one sample of a type of strategy she uses at least twice early on in the book: she mentions that since there was nothing really negative written about Sickert in his sister’s memoirs, entire sections of negative material must have been excised. Hello? She has no evidence that there ever was anything negative in the sister’s memoirs. All she knows is her own supposition that there must have been. And how does she know there must have been? Well, Sickert’s the Ripper, isn’t he?

One of the great divides in logic is between inductive and deductive reasoning. Inductive reasoning looks first at facts and information. It draws its conclusions from those facts–just like Sherlock Holmes does. (And don’t let Arthur Conan Doyle’s language fool you. He got the label wrong for Holmes’ “Science of Deduction”–which he should actually have termed the “Science of Induction“).

Deductive reasoning begins with a general principle and applies it to an individual instance of that principle. The deductive process could be represented like this:

•All men are mortal (general principle)
•Socrates is a man (individual instance of
principle).
•Therefore, Socrates is mortal (the deductive conclusion).

Inductive reasoning argues up from the specific to the general. Deductive reasoning argues down from the general to the specific.

So let’s take a look at the deductive process that leads Cornwell to conclude that negative material must have been excised from the sister’s memoirs.

Her starting supposition is that Walter Sickert is Jack the Ripper. Now, we don’t know whether she based this notion on an inductive process or whether she made an intuitive leap and somehow just knew he was the Ripper. But we can determine that this underlying supposition leads to the following line of deductive reasoning.

•(Sickert is Jack the Ripper)
•Jack the Ripper’s sister would naturally write terrible things about her brother in her memoirs. (general principle)
•The published memoirs of Jack the Ripper’s sister do not contain terrible things about her brother. (individual instance)
•Therefore, the terrible things that Jack the Ripper’s sister must have written had to have been censored for publication. (deductive conclusion).

The conclusion is logical if we start with the supposition that Sickert is the Ripper (which, once again, is the very point that it’s Cornwell’s job to prove) and if we assume that he was an absolutely dreadful child and young man and that his sister would have wanted to write about how dreadful he was. (She, of course, would not have known he was the Ripper… just that he was a famous painter).

Can you see some of the issues here? And I haven’t even gotten to the opening chapter yet. But, I’ll be back in a couple of days to provide yet more analysis of Cornwell’s argumentative strategies. Since she does have one of the more popular Ripper theories on the market today, it’s certainly worthwhile for members of her potential audience to know how she is presenting the case, and whether the argument she presents stands up to analysis.

I also have to say that I have not gotten far into the book yet. She may settle down as she goes, and focus on fact, and even present a good case and a good argument. If that occurs, I’ll be sure to report it. I mean, I have no dog in this fight… except a love of language and a distaste for seeing it used in order to manipulate an audience.

See the Blogcritics posting of this artcle.