Consequentialism is the ethical theory that holds that whether an act is morally good or bad depends only on the consequences.

Stanford Encyclopedia of Philosophy


Consequentialism as an ethical paradigm makes a claim about the justification of moral judgments. The focus is on why certain acts are morally good (bad or neutral). Another view is that consequentialism claims that “what matters is how well things go.”1Derek Parfit’s On What Matters, Volume 1, page 26. The idea is that moral judgments should be made by reference to what matters, which is how good or bad the situations are.

Consequentialism is typically used to refer to descendants of utilitarianism2See SEP. which may generalize beyond utility in the sense of measuring satisfaction alone while still adhering to the utilitarian paradigm3State consequentialism, for example, optimizes for the welfare of the state, which is not a direct aggregate of individual welfare.. The consequences prior to the act could be included in moral considerations, too4Derek Parfit notes in Reasons and Persons that if equitable consequences are desired over time, then one must factor in past consequences.. Strictly speaking, consequentialism does not need to be utilitarian, e.g., Rule Consequentialism: “Everyone ought to follow the principles whose universal acceptance would make things go best.”5Parfit’s On What Matters, Volume 1, page 23. One can easily imagine Virtue Consequentialism: “Everyone ought to live by the virtues whose universal adoption would make things go best.”6Rule Consequentialism could be argued as superior on consequentialist grounds to optimizing each action individually as per Act Consequentialism.

I found formalizing the consequentialist claim challenging: notions of dependence have not been formalized in SUMO and the precise meaning is unclear. Consequentialism is agnostic as to which protocol is used to determine whether an act is morally good or not. Formal precision seems to ask for less vagueness than is inherent in the definition. The intent seems to be that moral goodness should be determined by an analysis of the consequences; teleologically, the value of the consequences should be maximized. Determining the precise meaning of “consequences” is also tricky: we wish to include any facts about the real world. Does this perhaps mean that consequentialist judgments can depend on any physical entity and simply shouldn’t depend on abstract entities in the SUMO ontology?

Perhaps one could say that a justified ethical theory is consequentialist if all physical premises in the justifying arguments are consequences of the action under consideration and there is at least one physical premise, i.e., the moral judgments only depend on physical consequences and abstract entities, such as ethical axioms and inference rules. However, the abstract premises should only play the role of specifying how to analyze the consequences.

Another approach is to focus on consequentialist utilitarianism and to provide a constraint on the applicable utility functions so that anything influencing the output of the utility function is a possible outcome of the action concerned. Or, similar to utilitarianism, assume some measure of sets of consequences and provide relations between acts with (comparatively) good scoring consequences and moral goodness. This approach could perhaps be generalized to claim that the result of a moral judgment should only be influenced by physical consequences.


(documentation Consequentialism EnglishLanguage "Consequentialism is a moral theory that holds 
that 'whether an act is morally right depends only on consequences' (Stanford Encyclopedia of Philosophy).")
(subclass Consequentialism Ethics)    

(documentation ConsequentialistTheory EnglishLanguage "A set of consequentialist sentences.")
(subclass ConsequentialistTheory MoralTheory)

(theoryPhilosophyPair Consequentialism ConsequentialistTheory)