Permalink : http://hdl.handle.net/2115/35041

F.W. Lawvere described a certain interesting feature on G. Cantor's theory of cardinal numbers, using adjoint functors from the category theory. This paper provides a brief overview of the method he took, and then consider its significance. As a consequence, it is shown that he argues Cantor's theory of cardinal numbers in relationship to structured sets (specifically with topological structures,) and from the method we can get a hint to approach the nature of sets.