Since the beginning of modern philosophy, philosophers have struggled to establish that both the external and the internal worlds exist. This paper's author summarizes the positions of the strong idealists of the modern period such as Locke, Berkeley, and especially Hume. Next he establishes that some contemporary analytic philosophers question not the external world, but the internal world—posing the problem from another angle. The author then embarks on proving the existence of the external world in such a way that the internal world is not put into question. From what we know about logic, necessity, and rationality, it follows that the existence of physical objects depends merely on the existence of at least one rational being.
Jun, Nathan J.
"Necessary Truth and the Existence of External Objects,"
Episteme: Vol. 12
, Article 4.
Available at: http://digitalcommons.denison.edu/episteme/vol12/iss1/4