Regarding this provision, a researcher before the war Takeki OSATAKE interpreted narrowly that 'evil customs of the past' referred to national isolation as well as expulsion of foreigners and 'the just laws of Nature' meant international public law or international law, and he concluded this provision defined a policy of opening of the country to the world.
この条文を、戦前の研究者尾佐竹猛は、「旧来の陋習」は鎖国攘夷を指し、「天地の公道」は万国公法すなわち国際法の意味であり、この条文は開国の方針を規定したものとして狭く解釈していた。