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Post-normal science

Post-normal science (PNS) is a problem-solving framework developed by Silvio Funtowicz and Jerome Ravetz (1993) according to which a new conception of the management of complex science-related issues is proposed. The PNS framework was introduced at the inaugural conference of the International Society for Ecological Economics in 1990. In ‘normal’ science, uncertainty, value loadings and plural legitimate perspectives tend to be neglected, whereas according to the ‘post-normal’ view, these are integral elements to science particularly in the cases where facts are uncertain, values are in dispute, the stakes are high and decisions are urgent. Then a PNS strategy based on ‘extended peer review’ is advocated. However, when uncertainties and stakes are lower, an expert-based approach and traditional problem-solving strategies, such as applied science or professional consultancy, may be effective (Figure 1). For example, in relation to many environmental, health or sustainability issues, the answers provided by ‘normal’ science are necessary but not sufficient. In other cases, such as disputes on the health risks from asbestos or tobacco, ‘normal’ science finally wins the case. PNS provides a coherent framework for an extended participation in decision-making, whereby the quality assurance of policies relies on open dialogues between all those affected.

The main elements and principles of PNS include (Funtowicz and Ravetz, 1993):

• The scientific management of uncertainty and of quality

In the issue-driven research of PNS, the characteristic uncertainties are large, complex and less well understood than in matured quantitative sciences. Hence, the management of uncertainties should rely on explicit guidelines and credible set of procedures transparent to all the actors involved in a policy process. The principle of quality, understood as a contextual property of scientific information, is central to the management of uncertainty in PNS. It allows tackling the irreducible uncertainty and ethical complexity that are central to the resolution of complex issues. Consequently, PNS calls for the development of new norms of evidence and discourse, where knowledge is extended to peer communities for quality assurance purposes. Thus, one of the basic principles of PNS is the inclusion of laypersons, such as citizens and other non-experts in the assessment of quality. PNS recognizes that all those with a desire and commitment to participate in the resolution of the relevant issues are expected to enrich the nature of policy debates involving science.

• The multiplicity of perspectives and commitments

As policy processes become dialogue, knowledge is ‘democratised’, encompassing the diversity of legitimate perspectives and commitments. Again, the guiding principle in the dialogue on a PNS issue is quality rather than ‘truth’. Most complex issues entail a plurality of actors and multiple dimensions of analysis that are difficult to condense in a single scale of measurement. It is accepted that there is no sharp distinction between ‘expert’ and ‘lay’ constituencies. As a consequence, both types are needed to enrich the comprehension of the whole. Extending decision processes requires the creation of conditions to identify, involve and engage the relevant community, thus entering the realm of participatory processes. The contribution of social actors is understood not merely as a matter of broadening participatory democracy, but as a legitimate input to the co-production of knowledge. These extended peer communities are increasingly being created, with different forms and power arrangements, such as ‘citizens’ juries’, ‘focus groups’ or ‘consensus conferences’.

• The intellectual and social structures that reflect problem-solving activities

Unlike previous models of science, PNS does not attempt to define unifying conceptual foundations or to create closed boundaries in a field of research. Hence, the unity in PNS is primarily derived from an ethical commitment to the resolution of an issue rather than from a shared knowledge base. This commitment will take social actors through the appropriate problem-solving activities and dialogues.


Funtowicz, S., Ravetz, J. (1993) Science for the post-normal age, Futures 25 (7) 739–755.

For further reading:

Funtowicz, S., Ravetz, J. (1990) Uncertainty and Quality in Science for Policy. Kluwer Academic Publishers, the Netherlands.

Funtowicz, S., Ravetz, J. (1994) The Worth of a Songbird: Ecological Economics as a Post-normal Science, Ecological Economics, 10 (3)197-207.

Funtowicz, S., Ravetz, J. (Lead Authors); International Society for Ecological Economics (Content Partner); Robert Costanza (Topic Editor). (2008) Post-Normal Science; In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth September 18, 2006; Last revised December 22, 2008; Retrieved November, 11 2012]. <>

Useful websites:  

NUSAP – The Management of Uncertainty and Quality in Quantitative Information []

The Post-Normal Time []

This glossary entry is based on a contribution by Nuno Videira 

EJOLT glossary editors: Hali Healy, Sylvia Lorek and Beatriz Rodríguez-Labajos

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