contrastive は in negation

The particle は inserted before a negative element to mark contrast or emphasis on what is being negated — '*X*, that hasn't happened / *X*, that isn't the case.' Surfaces inside ~ていない (~てはいない: 恐れてはいなかった), inside i-adjective-continuative-with-ない (くは~ない: 美しくはない), and other negation contexts. Distinguishes 'X is not' from 'as for X, [it] is not.' Slightly stiffer and more deliberate than the unmarked negation.