Normative uncertainty is uncertainty about how to act given lack of certainty in any one normative theory, as well as the study of how one ought to act given this uncertainty.

Types of uncertainty

At the most basic level, uncertainty can be either descriptive or normative. Normative uncertainty can itself be either theoretical or practical. Within theoretical uncertainty, a further subdivision can be made between epistemological uncertainty and decision-theoretic uncertainty. And practical uncertainty can be subdivided into moral uncertainty and prudential uncertainty, while theoretical uncertainty can be subdivided into epistemological uncertainty and decision-theoretic uncertainty.

• Uncertainty
  • Descriptive
  • Normative
    • Theoretical
      • Epistemological
      • Decision-theoretic
    • Practical
      • Moral
      • Prudential

Some of these terms are not used consistently in the literature. In particular, what the taxonomy above calls 'practical uncertainty' is referred to as 'normative uncertainty' by some authors,^[1] and as 'moral uncertainty' by other (and sometimes even the same) authors.^[2][3][4]