3.3 The methods of Lord Peter Wimsey 35
3.3
The books noted as anthologies contain twenty-one short stories about
Lord Peter and some about other characters of Dorothy L. Sayers's inven-
tion. The other works are complete novels. The last two novels were com-
pleted by completed by Jill Paton Walsh based on material from Sayers.
Ian Carmichael starred in video versions of five of the Lord Peter adven-
tures. These were originally aired in the United Kingdom and subsequently
in the United States on PBS's Masterpiece Theater. Edward Petherbridge
starred in video versions of three other Lord Peter Mysteries, which were
aired first on the BBC and later on PBS's Mystery? series. Both of these
series have recently become available on videocassette and DVD.
3.2.3 The author behind Lord Peter Wimsey
Dorothy L. Sayers was born in Oxford, England, in 1893, the daughter of a
clergyman. She was fluent in Latin, French, and German and was one of
the first women to earn an Oxford degree in 1915. She was a scholar of
medieval literature. After World War I, she worked for the largest British
advertising firm. In 1926, she married the famous World War I correspon-
dent, Capt. O. A. Fleming. After writing the last Lord Peter novel, she
spent the rest of her life translating medieval literature and writing plays
and academic studies. She died in 1957.
There are a couple of important points to observe about Dorothy L.
Sayers. She was educated at Oxford, a scholar of history and of literature.
Despite her academic training, she was capable of earning her living first in
the business world and later as a writer. In these respects, the detective that
she created was made in her own image.
The methods of Lord Peter Wimsey
We can summarize the points of Lord Peter's methodology that apply to
software debugging under the following categories:
9 Use alibis as clues
9 Eliminate impossible causes
9 Exercise curiosity
9 Reason based on facts
9 Enumerate possibilities
I Chapter 3
36 3.3 The methods of Lord Peter Wimsey
3.3.1
9 Use the power of logic
9 Use a system for organizing facts
9 Exercise caution when searching
9 Use gestalt understanding
9 Show how something could be done
Applying Wimsey to debugging
Once again, we apply the analogy of viewing software defects as crimes to
be solved. We must answer the following questions:
9 Who did it?~suspect
[] How did the culprit do it?~means
[] When did the culprit do it?~opportunity
3.3.2
Our approach to motive is somewhat different, since we assume that all
defects were caused accidentally, as we explained previously. We are inter-
ested in an answer to the question, why did this problem happen? We treat
the why question the way an accident investigator would, rather than the
way a detective would. The detective seeks to assign guilt for a crime. The
investigator seeks to find contributing causes, to prevent the accident from
occurring again.
Use alibis as clues
In
Have His Carcase
[Sa32], Lord Peter works with the mystery writer Har-
riet Vane. They search for the murderer responsible for a body Harriet
found on a beach while on holiday. After a serious investigation, Lord Peter
works his way through a long chain of deductions while conversing with
one of the suspects:
"Always suspect the man with the cast-iron alibi"~was not that the
very first axiom in the detective's book of rules? And here it was~the
cast-iron alibi which really was cast-iron; meant to be scrutinized;
meant to stand every test~as how should it not, for it was truth!

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