I cant seem to understand this sentence
Sed hoc primum sentio nisi in bonis amicitiam esse non posse
But, this first, I feel friendship is [not] able to exist in good; [But i dont know what to do with nisi]
Sed. hoc primum, Sentio amictiam esse non posse in bonis
Well, in the first place I feel that friendship can exist only among the good
Does Nisi Negate non and make it only?