When it is said one must stand for something, it does not
mean that one must literally be standing, what is generally meant is that one
must figuratively fight for something he or she believes in. When it is said that someone falls for
something, it is generally meant that one either fell in love with something or
that one was deceived/is gullible. In
the instance of the quotation provided, however, what is meant is probably the
latter. That said, one interpretation of
the quotation, “A man who stands for nothing will fall for anything” is that if
one is not passionate about something or does not firmly believe in something,
one will easily believe in anything to the point of being easily fooled.
