poe

But it is in matters beyond the limits of mere rule that the skill of the analyst is evinced. He makes, in silence, a host of observations and inferences. So, perhaps, do his companions; and the difference in the extent of the information obtained, lies not so much in the validity of teh inference as in teh quality of the observation. The necessary knowledge is that of what to observe. (143)

Coincidences ten times as remarkable as this (the delivery of the money, and murder committed within three days upon teh party receiving it), happen to us every hour of our lives, without attracting even momentary notice. Coincidences, in general, are great stumbling-blocks in teh way of that class of thinkers who have been educated to know nothing of the theory of probabilities... (166)

Poe, Edgar Allen. "The Murders in the Rue Morgue." 141-176.