Sometimes one motive inspires the promoters of discovery, and another motive may inspire the individuals who carry out the search.
Herodotus concludes by saying, “Whether the sea girds Europe round on the north none can tell.” It was not Mediterranean folk but Northmen from Scandinavia, emigrating from their difficult lands centuries later, who carried exploration farther in the North Atlantic.
From the time of the earliest recorded history to the beginning of the 15th century, Western knowledge of the world widened from a river valley surrounded by mountains or desert (the views of Babylonia and Egypt) to a Mediterranean world with hinterlands extending from the Sahara to the Gobi Desert and from the Atlantic to the Indian Ocean (the view of Greece and Rome).
It later expanded again to include the far northern lands beyond the Baltic and another and dazzling civilization in the Far East (the medieval view).
Strong among them are the satisfaction of curiosity, the pursuit of trade, the spread of religion, and the desire for security and political power.
At different times and in different places, different motives are dominant.