Now that Australia has its long awaited legislation protecting the moral rights of authors, a new phase in the development of the rights begins. It must be asked how the incorporation of the rights into the existing copyright legislation, and their subjection to existing doctrines, will affect their operation. And how will existing doctrines be challenged and extended by the existence of the rights? Ultimately these questions will be worked out in the courts. The present article offers a consideration of one area where the legislature has purported to integrate moral rights into the existing scheme but where the practicalities oftheir integration are still unclear. It examines the interplay of moral rights with the doctrine of substantiality, suggesting that any clarification of what substantiality means in the moral rights context will be contingent upon the emergence of more precise definitions of what moral rights are and what interests they are intended to protect.