ABSTRACT
In this chapter, the author aims to clarify the large variety of definitions of the concept of sustainability by pointing out their distinguishing features. He explores whether there is anything to be gained by making a distinction between the concepts of 'weak' and 'strong' sustainability. The author explains definitions within the agricultural sector in an attempt to find an operational definition of sustainable agricultural practice and of established agricultural systems that conform to the definition and which, by implication, offer models of sustainable agriculture. A normative orientation of sustainability requires an assessment and evaluation framework that should be able to test states of the economy and the ecology against a set of reference values. This approach requires three important components in any sustainability analysis: a set of measurable sustainability indicators, a set of normative reference values and a structured impact and evaluation methodology for assessing developments.
