Although the cousience and character of a good doctor are sufficient on their own to allow us to discuss and make decisions regarding very difficult ethical subjects in transplantation, basic ethical principles commonly used in medicine must also be applied to various aspects of organ donation. Some system has to be adopted that assesses the weight that must be given to various possible solutions. For example, would live donor transplantation still be acceptable if there were a surfeit of cadaveric organs? If animal organs can be transplanted successfully, is that more desirable than using human organs: particularly if human donation involves interventional ventilation or non-heart beating donors? Is interventional ventilation more "ethical" than live donor liver or lung transplantation? No doubt future developments in transplantation, opening more opportunities for the successful treatment of more patients, are likely to produce increasingly difficult ethical issues. Discussions of these issues must be firmly based on principles of medical ethics, although accepting that whilst absolute principles may be available, absolute answers are more difficult to come by.