Final answer:
Persuasion and arguments to convince others to join the expedition to Greenland emphasized adventure, escape from imprisonment, and historical precedence of Norse explorations. The expeditions by Portugal and Spain in the fifteenth century also contributed to the viability of colonizing Greenland.
Step-by-step explanation:
To convince others to join him on an expedition to Greenland and establish a new colony, various persuasion and arguments were employed. For some, the allure of adventure and the glory of exploring unknown places peaked their interest. Others were motivated by the opportunity to escape a life of imprisonment, with hopes of a better future found in uncharted lands.
Additionally, knowledge of previous Norse explorations to North America, such as Leif Erikson's colony in Newfoundland, served as evidence that it was possible to establish successful colonies in the region. This historical precedence likely helped in persuading others that Greenland could be a viable and habitable land for colonization.
Lastly, explorers sailing for Portugal and Spain during the fifteenth century played a significant role in dispelling the uncertainties regarding the existence of American continents and the Pacific Ocean. Their expeditions led to permanent contact with North America and opened up the possibility of successful colonization ventures.