|Metaphors may help understand the process of deduction|
Watson gamely struggles with various metaphors to describe the process of deduction, so that the unfamiliar can be illuminated by analogy with the familiar.
Deduction is the unravelling of a tangled ball of twine.
There's plenty of thread, no doubt, but I can't get the end of it into my hand [TWIS].
--- to devise some common thread upon which they might all hang [MUSG].
--- you broke the thread of my thoughts. --- I have now in my hands all the threads which have formed such a tangle [STUD].
Different threads, but leading up to the same tangle [RUDC].
There is a thread here which we have not yet grasped and which might lead us through the tangle [DEVI].
It is a tangled skein, you understand, and I am looking for a loose end [CREE].
There's the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose every inch of it [STUD].Deduction is the forging of a chain of links.
It is so long a chain, and yet every link rings true [REDL].
The last link. My case is complete [STUD].
I only require a few missing links to have an entirely connected case [SIGN].
It's the chain between them that we are going to trace [VALL].
It was by concealing such links in the chain that Watson was enabled to produce his meretricious finales [BLAN].
When you follow two chains of thought, Watson, you shall find a point of intersection which will approximate the truth [LADY].Deduction is the playing of a game of cards.
We are getting some cards in our hand. --- it is not an easy one to play [SHOS].
We have added one card to our hand [SHOS].
Alas that I should have to show my hand so when I tell my own story [BLAN].Each metaphor, I must confess, he took from my own mouth - or, in some cases, put into my mouth. The thread metaphor is so mixed that it, in itself, is a tangled ball. I further confess that the metaphors got mixed, with two or more metaphors within a single case - indeed, even within a single paragraph. Metaphors are helpful aids to make concrete what is basically an abstract process. However, now that I have the leisure to contemplate my career, I believe that the most useful metaphor for what I was doing is that I was telling a story. Since this metaphor applies not so much to deduction per se but to the entire process of detection, I will explore it at more length in Chapter 8 - Explanation.