This is not a conventional PhD. It is a PhD based on published work. The unifying theme is the study of the extent to which commercial law is able to adapt to changing business needs. The conventional view in academic law is that commercial law is sufficiently flexible to be adapted to the developing needs of business, but to what extent is this true? The existing literature provides many examples of how commercial law has been adapted to modern commercial conditions by various mechanisms and how its defects, omissions and inconsistencies have been overcome. However, this literature also provides examples of where there have been significant gaps between commercial law and commercial reality, which have remained unbridgeable for prolonged periods of time. The topics chosen, and the examples given, by the previous authors have been selective; often by necessity. It is based on the recognition that in a field as vast as commercial law, the authors know that they have to strike a balance between the competing claims of coverage, detail and depth, and that where they have chosen the option of depth; they have had to be selective. These authors have not claimed that their work should be regarded as comprehensive statements on the adaptability of commercial law. Instead, they have based their conclusions on the evidence acquired from the relatively narrow field of study. The implications of this are that their conclusions, which are based on a restricted set of data, may be potentially refutable, or subject to amendment in the light of new data. My work supplies additional analytical data. I do not aim to provide a definitive and comprehensive assessment of the extent to which commercial law is flexible. The subject is too vast. So, like past authors, I too have been selective. My choice of topics within commercial law sometimes overlaps with, and sometimes differs from, what has been examined in the past. In either case my aim is to produce new knowledge about the extent to which commercial law has been able to meet business needs in certain developing areas. Like the previous researchers I have chosen to examine issues that are in the core areas of commercial law (such as the sale of goods and bankruptcy). However, I have also examined topics where new and significant developments have occurred and where new evidence can be brought to bear on this central theme. This entails examining areas of business activity that have been neglected or overlooked by previous academics who have been exploring the theme of the flexibility of commercial law. These academically neglected topics of study are, nonetheless, important in commercial practice and they include the topics of franchising and securitisation. The resulting research has produced a new data set, which is variously able to confirm, refute and supplement the knowledge that already exists about the nature of commercial law. Concerning methodology, in keeping with other authors, I have employed a doctrinal analysis to the issues addressed in some of the publications. From a doctrinal perspective, commercial law is viewed as a system that is generally rational and coherent, where contradictions, gaps, and ambiguities need to be identified and, so far as is possible, eliminated. I have adopted the conventional view that the law ought to be adaptable and flexible to meet the needs of business (within the bounds of public policy) and that this goal should serve as a criterion for judging legal developments and proposed reforms. Working within this framework and pursuing modes of thought conventional to the doctrinal approach, the explanatory essay (which forms a preface to the published works) shall highlight some of new facts and insights contained in the submitted publications that lend support to a commonly accepted pattern of commercial law analysis. This approach is not designed produce a paradigm shift in the subject. However, it does extend the boundaries of the subject and aid understanding about the flexible nature of commercial law. It shows the extent to which the law can be adapted to meet the expectations of business and how it balances the need for legal certainty in transactions with the conflicting needs for flexibility and the protection of the public interest. The doctrinal approach of the published research may also serve to assist lawyers in dealing with technical legal problems and assist reformers by focusing attention on deficiencies in the law that require remediation. As a contribution to commercial law, the publications reveal is that different areas of commercial law are moving at different speeds and display different degrees of flexibility, and are subject to different levels of statutory or regulatory intervention. The publications have also shown that the negative forces of drift and inertia in some areas can sometimes be as significant as the forces of economic change on the law. Drift occurs where an inappropriate rule remains unchanged for a long period of time because the practitioners have found a way around the problem, or because businesses are not prepared to litigate on the issue, thereby reducing demands for change. This state may continue until a sudden increase in transaction costs or an adverse court ruling produces an urgent demand for reform. With respect to inertia, it has been noted that Parliament has often been disinterested in legislating in the commercial field, relying on the existence of the many old statutory enabling and default rules to permit a degree of flexibility and development in commercial law. It has convinced many governments, even in recent times, that routine legislative review of the law is not required. As a consequence, it has often been difficult to persuade governments to find time to modernise commercial law, even where the common law has failed to cope adequately with new commercial developments. Despite these problems, commercial law remains one of the most dynamic areas of law. It is continually evolving to try to meet the new needs of business even although there are limits to its adaptability. The challenge remains to find a way to ensure that commercial law responds more appropriately to changing business needs by understanding more about the mechanisms of legal development in commerce.