Editing Utilitarianism (section)

=== Predicting consequences ===
Some argue that it is impossible to do the calculation that utilitarianism requires because consequences are inherently unknowable. [[Daniel Dennett]] describes this as the "[[Three Mile Island accident|Three Mile Island]] effect".<ref>Dennett, Daniel (1995), ''Darwin's Dangerous Idea'', Simon & Schuster, p. 498 {{ISBN|0-684-82471-X}}.</ref> Dennett points out that not only is it impossible to assign a precise utility value to the incident, it is impossible to know whether, ultimately, the near-meltdown that occurred was a good or bad thing. He suggests that it would have been a good thing if plant operators learned lessons that prevented future serious incidents.

Russell Hardin (1990) rejects such arguments. He argues that it is possible to distinguish the moral impulse of utilitarianism (which is "to define the right as good consequences and to motivate people to achieve these") from our ability to correctly apply rational principles that, among other things, "depend on the perceived facts of the case and on the particular moral actor's mental equipment."<ref>{{cite book |last=Hardin |first=Russell |title=Morality within the Limits of Reason |publisher=University of Chicago Press |date=May 1990 |page=3 |isbn=978-0-226-31620-8}}</ref> The fact that the latter is limited and can change does not mean that the former has to be rejected. "If we develop a better system for determining relevant causal relations so that we are able to choose actions that better produce our intended ends, it does not follow that we then must change our ethics. The moral impulse of utilitarianism is constant, but our decisions under it are contingent on our knowledge and scientific understanding."<ref name="Hardin 1990 4"/>

From the beginning, utilitarianism has recognized that certainty in such matters is unobtainable and both Bentham and Mill said that it was necessary to rely on the ''tendencies'' of actions to bring about consequences. [[G. E. Moore]], writing in 1903, said:<ref>{{cite book |last=Moore |first=G. E. |title=Principia Ethica |publisher=Prometheus Books UK |year=1903 |pages=203–4 |isbn=978-0-87975-498-3}}</ref>
{{blockquote|We certainly cannot hope directly to compare their effects except within a limited future; and all the arguments, which have ever been used in Ethics, and upon which we commonly act in common life, directed to shewing that one course is superior to another, are (apart from theological dogmas) confined to pointing out such probable immediate advantages{{nbsp}}...

An ethical law has the nature not of a scientific law but of a scientific ''prediction'': and the latter is always merely probable, although the probability may be very great.}}