There have been several attempts to establish a typology of uncertainty and ignorance in economic and environmental risk studies for the last hundred years. These are, however, mostly oriented to societal decision making, which hinders our understanding of whether such incertitude is intrinsic or extrinsic, blurring boundaries between science and society. By referring to the distinct domains of the real, the actual, and the empirical in critical realism and corresponding them to ontology, epistemology and methodology as foundations in philosophy of science, a novel typology forms a stratified structure of incertitude. This heuristic also breaks the actual domain into two strata on human sensory and meaning, and further divides each stratum by the scope of science−object, system, social interaction with the system, and general. It finally identifies fifteen types of incertitude in science and discusses their relevance by taking seismology as an example. Being well aware of the diversity and inevitability of such incertitude, scientists are expected to undertake their enterprise with scientific discipline and social responsibility.

The concept of trans-science by A. Weinberg is reexamined in connection with a huge and advanced science project, KEK B factory. Classification of the trans-science is introduced which implies the similarity with the uncertainty matrix approach of A. Stirling. The similarity is extended to the post normal science of J. Ravetz. Treatment of these uncertainties is a key issue for a successful huge engineering project.

　 What disaster sciences are expected by the society is to prevent or mitigate future natural disasters, and therefore it is necessary to foresee natural disasters. However, various constraints often make the foreseeing difficult so that there is a high incertitude in the social contribution of disaster sciences. If scientists overstep this limitation, they will be held even criminally responsible. The L’Aquila trial in Italy is such a recent example and so we have performed data collections, hearing investigations, analyses of the reasons for judgment, etc., to explore the incertitude of disaster sciences and scientists' responsibilities. As a result, we concluded that the casualties during the L’Aquila earthquake were mainly due to a careless “safety declaration” by the vice-director of the Civil Protection Agency, where the incertitude of disaster sciences had never been considered. In addition, news media which reported only this “safety declaration” were also seriously responsible for the casualties. The accused other than the vice-director were only morally responsible, because their meeting remarks included poor communication in disaster sciences but those were not reported to the citizens in advance to the L’Aquila earthquake.

　 Discussion on the social implication of antenatal testing technology has become active in Japan, yet again, since the announcement that provision of the “new antenatal test” will start in the end of August，2012. Based on the critiques on “medicalization” in the field of medical sociology and “domination of human life by expertise” in the field of Science and Technology Studies, the paper argues that the prenatal testing technology is the devise for medical expertise to dominate human life. In order to against this invasion of our autonomy for human life, it is necessary to relativize medical expertise within various forms of knowledge about human life that exist in society. Knowledge based on the experience of people, whom medical expertise categorizes as “anomaly”, is especially important in this context. The paper lastly introduces a project purporting to share the experience of people with trisomy of chromosome 21, one of the targets of prenatal testing technologies.