Interest in western science among early Chosŏn Catholics had played a great role in their accepting of Catholicism. Indeed, many Catholics chose, as a method for the propagation of Catholicism, the use of western science to overcome a crisis that they had faced since 1785. Around 1789 King Chŏngjo launched large scale reformation of astronomical, geographical, and military practices and knowledge. It was for this reason that Chosŏn Catholics thought that King Chŏngjo would welcome western missionaries provided they brought with them western scientific knowledge. They believed that western missionaries, by helping King Chŏngjo's reformation policy, would reduce hostility towards Catholicism. Moreover, They believed that the arrival of missionaries would not only allow them to live safely as Catholics, but that it would also allow them personally to contribute to King Chŏngjo's plans for enhancing Chosŏn's prosperity and defense. However, as they came to realize the difficulty involved with inviting western missionaries from China, Chosŏn Catholics requested that the bishop in Peking send a 'big western vessel'. When they called for a 'big western vessel' they were asking for western missionaries to come directly from Euroupe to Chosŏn with a big ship filled with western scientific instruments and valuables.
Due to the circumstance of Peking Church this wish of Chosŏn Catholics was not fulfilled. Nevertheless, Chosŏn Catholics were not daunted and continued to entreat the bishop in Peking until demise of King Chŏngjo. The reason was that they were well aware of King Chŏngjo's interest in western science, and places their hopes in him.
However, when Chosŏn Catholics confronted a serious crisis following King Chŏngjo's death and wholesale religious persecution in 1801, Hwang Sa Young thought of more extreme methods. Nevertheless, Hwang's idea was obviously exceptional, as is revealed both by his writings and by his statement after arrested. Especially, in 1811 a letter sent to the Pope and the bishop in Peking, written by people who had studied under the early leaders of Chosŏn Catholic Church revealed the attitudes of the early Chosŏn Catholics. The letter revealed not only their thoughts about western ships, but also their devotion to and concern for King Sunjo, despite his severe persecution of Catholics.
Clearly, then, Chosŏn Catholics' requests that western missionaries and a vessel be sent to Korea were not made with the intention of obtaining freedom of worship through western military threats to King Chŏngjo and the Chosŏn government. Furthermore, it makes no sense to claim that they were influenced by Chŏngkamnok (鄭鑑綠), and that they therefore intended to use western military power to overthrow the Chosŏn government and establish an ideal new world. The lives and confessions of faith of the people who made these request~, as well those of their family or friends, do not support such a conclusion. Indeed, the early Catholics rejected the cult of prominent figures and refused to follow unorthodox doctrines. They lead a life of faith and offered their lives to God, King of Kings, God the Father and the origin of human beings.