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Wednesday, July 21, 2021

The Parliamentary Approach to Moral Uncertainty

Toby Newberry & Toby Ord
Future of Humanity Institute
University of Oxford 2021


We introduce a novel approach to the problem of decision-making under moral uncertainty, based
on an analogy to a parliament. The appropriate choice under moral uncertainty is the one that
would be reached by a parliament comprised of delegates representing the interests of each moral
theory, who number in proportion to your credence in that theory. We present what we see as the
best specific approach of this kind (based on proportional chances voting), and also show how the
parliamentary approach can be used as a general framework for thinking about moral uncertainty,
where extant approaches to addressing moral uncertainty correspond to parliaments with different
rules and procedures.

Here is an excerpt:

Moral Parliament

Imagine that each moral theory in which you have credence got to send delegates to an internal parliament, where the number of delegates representing each theory was proportional to your credence in that theory. Now imagine that these delegates negotiate with each other, advocating on behalf of their respective moral theories, until eventually the parliament reaches a decision by the delegates voting on the available options. This would provide a novel approach to decision-making under moral uncertainty that may avoid some of the problems that beset the others, and it may even provide a new framework for thinking about moral uncertainty more broadly.


Here, we endorse a common-sense approach to the question of scale which has much in common with standard decision-theoretic conventions. The suggestion is that one should convene Moral Parliament for those decision-situations to which it is intuitively appropriate, such as those involving non-trivial moral stakes, where the possible options are relatively well-defined, and so on. Normatively speaking, if Moral Parliament is the right approach to take to moral uncertainty, then it may also be right to apply it to all decision-situations (however this is defined). But practically speaking, this would be very difficult to achieve. This move has essentially the same implications as the approach of sidestepping the question but comes with a positive endorsement of Moral Parliament’s application to ‘the kinds of decision-situations typically described in papers on moral uncertainty’. This is the sense in which the common-sense approach resembles standard decision-theoretic conventions.