On this website I present Moral Decision Theory. This is the view that prescriptive statements can be objectively true, with their truth grounded in the logic of decisions. I explain the axioms of the theory, provide justification and comparison to other metaethical positions, and explore some applications.

Conventional decision theory concerns how agents make choices which satisfy their own desires. Although these desires are subjective, the logic used to determine which course of action will best satisfy those desires is objective.

Beyond this, Moral Decision Theory recognises that there is no universal or categorical reason for an agent to prioritise the desires of any particular individual, including themselves. Logic is free from bias, even bias towards oneself. Therefore, the rational agent ought to make impartial decisions.

Agents are uncertain about the consequences of their actions, and about the desires of others, but this does not preclude reason. Objectively true moral statements can thus be made about which course of action one ought to choose in a certain situation.


Moral Decision Theory is consistent with naturalism but does not fall victim to the criticisms levelled against other meta-ethical positions.

Part 1
Moral Decision Theory
In Principle


1.1 Terminology

1.2 Our Decisions Ought to be Logical