Are reference cycles bad form?

[Roy Smith]

Manuel Garcia <news at manuelmgarcia.com> wrote:
> But as a general pricipal, is a design without reference cycles better
> than a design with them?

I think that's a little like asking if singly-linked lists are better 
than doubly-linked lists.  Does your child ever need to know who its 
parent is?  If so, then it probably makes sense to store the reference.

I don't see that there's any "general principal" here one way or the 
other.