Nevertheless, the theoretical possibility, and its realization in many cases, has brought considerations to the front which have recently become of predominant interest; consequently the possible transformations of isomers and polymers will be considered later under the denomination of reversible or dynamical isomerisms.
The ending message is also very different, not good or bad, just take your own lesson from each.
Not a great opera, perhaps, but nevertheless a very interesting one, its disturbing theme clinging naggingly to the conscience in a way than more sumptuous fare rarely does.