Sherlock Holmes, Red Teamer

A really good point and explanation at the Red Team Journal.

Holmes explains to Dr. Watson the ability to “reason backwards”:

In solving a problem of this sort, the grand thing is to be able to reason backwards. That is a very useful accomplishment, and a very easy one, but people do not practise it much. In the every-day affairs of life it is more useful to reason forwards, and so the other comes to be neglected. There are fifty who can reason synthetically for one who can reason analytically…. Let me see if I can make it clearer. Most people, if you describe a train of events to them, will tell you what the result would be. They can put those events together in their minds, and argue from them that something will come to pass. There are few people, however, who, if you told them a result, would be able to evolve from their own inner consciousness what the steps were which led up to that result. This power is what I mean when I talk of reasoning backwards, or analytically.

As red teamers, we often posit what the adversary wants (“a result”) and then “evolve from [our] own inner consciousness what the steps were which led up to that result.” Whether all red teamers do, in fact, have an “inner consciousness” is an open question, but at least when it comes of reasoning backwards, nearly all of us share this ability with the great Mr. Holmes.