Clare Winnicott wrote about her husband that the ability to play "was part of his way of putting himself into and being in relations" and "of his entire way of living". Playing and Reality was published posthumously, as many will know, but his theory of playing had long been in preparation over the course of his life. At the heart of playing lies the fact of its being consigned to potential space and its making use of transitional qualities. In this way, it combines intrapsychic experiences with input coming from the outside world, and uses whatever is provided by the interlocutor or external phenomena for internal re-elaborations. Playing effectively takes different forms according to the stage of life one is in, even if the process of playing is the same whether with infants or with adults. Winnicott considered the most important component of playing to be its creative moment.