The primary thing when you take a sword in your hands is your intention to cut the enemy, whatever the means. Whenever you parry, hit, spring, strike or touch the enemy’s cutting sword, you must cut the enemy in the same movement. It is essential to attain this. If you think only of hitting, springing, striking or touching the enemy, you will not be able actually to cut him.
The McNamara fallacy, named for Robert McNamara, the US Secretary of Defense from 1961 to 1968, involves making a decision based solely on quantitative observations (or metrics) and ignoring all others. The reason given is often that these other observations cannot be proven.
The fallacy refers to McNamara's belief as to what led the United States to defeat in the Vietnam War—specifically, his quantification of success in the war (e.g., in terms of enemy body count), ignoring other variables.
The details are fascinating, but the central argument — that the birth of modernity can be traced to a meta-crisis spawned by the 0.1s problem — is worth understanding and appreciating whether or not you’re a time nerd like me.
There is no convenient leitmotif, comparable to the 0.1s problem, for our contemporary version of the rhyming conditions, but something very similar to the “tenth of a second crisis” is going on today. I suspect our Great Weirding too involves some sort of limiting factor on human cognition that we haven’t yet properly wrapped our minds around. It isn’t reaction time, but something analogous.