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.
And what is delight? For me, delight is born from a tool’s intuitiveness. Things just working without much thought or fiddling. Delight is a simple menu system you almost never have to use. Delight is a well-balanced weight on the shoulder, in the hand. Delight is the just-right tension on the aperture ring between stops. Delight is a single battery lasting all day. Delight is being able to knock out a 10,000 iso image and know it'll be usable. Delight is extracting gorgeous details from the cloak of shadows. Delight is firing off a number of shots without having to wait for the buffer to catch up. Delight is constraints, joyfully embraced.