the mind > attention and judgement > attention > notice, observation > [noun] > closeness of observation (4)
= vigilance, n. 1 (Very common 1550–1700.)
The quality or character of being vigilant; watchfulness against danger or any action on the part of others; alertness or closeness of observation…
The quality or state of being watchful or attentively observant; vigilance.
Keenness (of observation).