[Bioethics after 50 Years: A Reflection on the need to restore human biology to its proper place]

The development of Bioethics over approximately half a century makes it possible, with sufficient historical perspective, to recognise the existence of two major phases regarding the place that positive science has occupied within the broader set of modes of human knowledge. In an initial phase, which can be situated in the last quarter of the twentieth century, science was regarded not only as the most solid knowledge available but, in many contexts, as the only truly reliable form of knowledge. This position did not merely acknowledge the methodological value of science; it tended to absolutise it, attributing to it the capacity to answer any relevant question about reality. Subsequently, during the first quarter of the twenty-first century, an apparently opposite phenomenon has emerged. Science has begun to be regarded as dispensable or irrelevant when its results do not support certain ideological constructions, or even when they come into conflict with them. In this way, the cultural authority of science ceases to depend on its capacity to describe reality and instead becomes dependent on its usefulness in sustaining particular pre-existing interpretative frameworks. Within this historical and intellectual context, it becomes necessary to restore biological truths to their proper place within the overall system of human knowledge and within the body of ideas that shape Culture. Only if Biology occupies this appropriate place will it be possible for Bioethics to achieve genuine interdisciplinarity, capable of integrating simultaneously the natural meaning of biological processes with their human significance. It is precisely in this integration that ethical judgement in the sphere of human corporeality consists. The resistance of Nature to certain manipulations should not be interpreted merely as a technical difficulty, but rather as an indication of the existence of real natural limits. These limits do not disappear simply because human beings possess technological means with which to attempt to overcome them. When such limits are systematically ignored, science runs the risk of turning into science fiction. This transformation may be encouraged by economic interests linked to future technological promises which, on occasion, end up promoting fraud within scientific research itself. The debate surrounding cloning constitutes a paradigmatic example of this process. On the other hand, the scientific arguments that at a given moment allow a fact to be affirmed should never be regarded as absolutely definitive. The emergence of new data requires arguments to be continually revised and refined. A particularly relevant example in this regard is the current updated scientific elaboration concerning the personal character of the human zygote and, in connection with this, the understanding of the origin of monozygotic twins.