other hand, which of all those things that would seem to us easy
to accomplish or know in the future, may actually turn out to be hard or
among the hardest of possibilities?

<P>What were the hardest problems historically and how were they solved?
Moreover, what resulted from their solution or explanation-and what lessons
may there be for us now as we confront those things that for ourselves
are the hardest to come to terms with?

<P><A NAME="Heirarchies"></A><B><FONT SIZE=+1>Describe Hierarchies</FONT></B>