What is the meaning of nice?

Nice is the least of all descriptions. 
Always accompanied by a just out 
reach but. The hint of crimes and
misdemeanours, great and small, 
hiding behind a curtain 
drawn with an empty pen.

When you have nothing good to say,
say nothing at all -  but if you are
compelled to speak, say nice.
When did the first law of discourse, 
passed down from the original source,
morph into the need for nice?

Nice is the death of the possibility
of romance, the end of the beginning
of friendship, the ultimate waffle of 
admission that one could be wrong.
And so, in circumstances now obliged, 
we have the greatest hedge of all the bets, 
the nice that is a source of nothing at all.