Commensurability (ethics)
Encyclopedia
In ethics
, two value
s (or norms
, reasons
, or goods) are incommensurable when they do not share a common standard of measurement.
Philosophers argue over the precise nature of value incommensurability, and discussions do not always exhibit a consistent terminology. It is frequently said that two values are incommensurable if and only if, when compared, neither is better than the other nor are they equally valuable. This result does not follow from the strict definition of incommensurability (absence of a common standard of measurement). Thus some prefer to use "incommensurable" when describing pairs that lack a common measure and to use the word "incomparable" more specifically when describing incommensurable pairs containing members neither of which is better than or equal to the other.
Philosophical reflection about practical reason
typically aims for a description of the principles relevant in answering the question, "What is to be done in this or that circumstance?" On one popular view, answers to this question can be found by comparing the relative strengths of the various values or norms in play in some given situation. For example, if one is trying to decide on some nice afternoon whether they should stay in to do work or go for a walk, on this view of practical reason they will compare the merits of these two options. If going for a walk is the better or more reasonable course of action, they should put aside their books and go for a stroll. The topic of incommensurability--and the topic of incomparability in particular--is especially important to those who advocate this view of practical reason. For if one's options in certain circumstances are of incomparable value, he or she cannot settle the question of what to do by choosing the better option. When the competing options are incomparable, then by definition neither is better than the other.
In recent decades, incommensurability has figured prominently in recent philosophical debates over the possibility of moral dilemmas and the plausibility of certain forms of consequentialism
in ethics. The incommensurability of various types of moral reason is often seen as explaining how moral dilemmas and other ethical conflicts might be possible. Incommensurability also presents a prima facie
challenge to ethical theories that contend that the right thing to do is the action that promotes the most overall good; if value incommensurability is widespread enough to make most values incommensurable with one another, then it seems that the utilitarian calculus is not even theoretically possible.
The topic of incommensurability has also frequently arisen in discussions of the version of natural law
theory associated with John Finnis
and others.
Ethics
Ethics, also known as moral philosophy, is a branch of philosophy that addresses questions about morality—that is, concepts such as good and evil, right and wrong, virtue and vice, justice and crime, etc.Major branches of ethics include:...
, two value
Value theory
Value theory encompasses a range of approaches to understanding how, why and to what degree people should value things; whether the thing is a person, idea, object, or anything else. This investigation began in ancient philosophy, where it is called axiology or ethics. Early philosophical...
s (or norms
Norm (philosophy)
Norms are concepts of practical import, oriented to effecting an action, rather than conceptual abstractions that describe, explain, and express. Normative sentences imply “ought-to” types of statements and assertions, in distinction to sentences that provide “is” types of statements and assertions...
, reasons
Practical reason
In philosophy, practical reason is the use of reason to decide how to act. This contrasts with theoretical reason , which is the use of reason to decide what to believe. For example: agents use practical reason to decide whether to build a telescope, but theoretical reason to decide which of two...
, or goods) are incommensurable when they do not share a common standard of measurement.
Philosophers argue over the precise nature of value incommensurability, and discussions do not always exhibit a consistent terminology. It is frequently said that two values are incommensurable if and only if, when compared, neither is better than the other nor are they equally valuable. This result does not follow from the strict definition of incommensurability (absence of a common standard of measurement). Thus some prefer to use "incommensurable" when describing pairs that lack a common measure and to use the word "incomparable" more specifically when describing incommensurable pairs containing members neither of which is better than or equal to the other.
Philosophical reflection about practical reason
Practical reason
In philosophy, practical reason is the use of reason to decide how to act. This contrasts with theoretical reason , which is the use of reason to decide what to believe. For example: agents use practical reason to decide whether to build a telescope, but theoretical reason to decide which of two...
typically aims for a description of the principles relevant in answering the question, "What is to be done in this or that circumstance?" On one popular view, answers to this question can be found by comparing the relative strengths of the various values or norms in play in some given situation. For example, if one is trying to decide on some nice afternoon whether they should stay in to do work or go for a walk, on this view of practical reason they will compare the merits of these two options. If going for a walk is the better or more reasonable course of action, they should put aside their books and go for a stroll. The topic of incommensurability--and the topic of incomparability in particular--is especially important to those who advocate this view of practical reason. For if one's options in certain circumstances are of incomparable value, he or she cannot settle the question of what to do by choosing the better option. When the competing options are incomparable, then by definition neither is better than the other.
In recent decades, incommensurability has figured prominently in recent philosophical debates over the possibility of moral dilemmas and the plausibility of certain forms of consequentialism
Consequentialism
Consequentialism is the class of normative ethical theories holding that the consequences of one's conduct are the ultimate basis for any judgment about the rightness of that conduct...
in ethics. The incommensurability of various types of moral reason is often seen as explaining how moral dilemmas and other ethical conflicts might be possible. Incommensurability also presents a prima facie
Prima facie
Prima facie is a Latin expression meaning on its first encounter, first blush, or at first sight. The literal translation would be "at first face", from the feminine form of primus and facies , both in the ablative case. It is used in modern legal English to signify that on first examination, a...
challenge to ethical theories that contend that the right thing to do is the action that promotes the most overall good; if value incommensurability is widespread enough to make most values incommensurable with one another, then it seems that the utilitarian calculus is not even theoretically possible.
The topic of incommensurability has also frequently arisen in discussions of the version of natural law
Natural law
Natural law, or the law of nature , is any system of law which is purportedly determined by nature, and thus universal. Classically, natural law refers to the use of reason to analyze human nature and deduce binding rules of moral behavior. Natural law is contrasted with the positive law Natural...
theory associated with John Finnis
John Finnis
John Finnis , is an Australian legal scholar and philosopher, specializing in the philosophy of law. He is Professor of Law at University College, Oxford and at the University of Notre Dame, teaching jurisprudence, political theory, and constitutional law...
and others.