Boundaries between the continents of Earth Boundaries between the continents of Earth The boundaries between the continents of Earth are generally a matter of geographical convention. Several slightly different conventions are in use. The number of continents is most commonly considered seven but may range as low as four when the Americas and Afro-Eurasia are each considered a single continent. According to the definition of a continent in the strict sense, an island cannot be part of any continent, but by convention and in practice most major islands are associated with a continent. There are three overland boundaries subject to definition: While the isthmus between Asia
Continent the "continents" (or mainlands) of Isle of Man, Ireland and Wales and in 1745 to Sumatra. The word "continent" was used in translating Greek and Latin writings about the three "parts" of the world, although in the original languages no word of exactly the same meaning as "continent" was used. While "continent" was used on the one hand for relatively small areas of continuous land, on the other hand geographers again raised Herodotus's query about why a single large landmass should be divided into separate continents. In the mid-17th century, Peter Heylin wrote in his "Cosmographie" that "A Continent is