1. McLaughlin, 1955, p.400–402.
2. Von Wright, 1956, p.508.
3. Von Wright, 1956, p.508.
4. Ross, 1968, p.143,144.
5. Cf. Ross, 1968, p.141. Ross does, however, not profess this respect for ‘common sense’ in the context which is at issue here, but in discussing authors in whose opinion deontic logic is impossible.