Brain in a skull

The Blank Slate

From: http://www.lukesurl.com/

The naturalistic fallacy

This term loosely describes arguments that claim to draw ethical conclusions from natural facts; for instance penguins are monogamous and therefore humans should be. G E Moore  formally identified the naturalistic fallacy as any attempt by ethical philosophers to prove or back up a claim by defining good in terms of one or more natural properties (such as 'pleasant', 'more complex', 'desired', and so on).

The naturalistic fallacy assumes that because the words 'good' and, say, 'pleasant' can be used to describe the same object, they must be describing the same attribute. A good cheese will clearly taste pleasant, but a good bomb is one that kills most people.  

The naturalistic fallacy is related to, but should not be confused with, the is-ought problem. .

The Open Question Argument

Many moral religious and moral philosophers have attempted to equate good either with a deity (God is good) a divine command (what is pleasing to God) or with some natural phenomenon (pleasure is good). The Open Question Argument was formulated by G. E. Moore in his 1903 work Principia Ethica in order to refute such identifications. The argument is as follows:

(Premise 1) If X is good, then the question "Is it true that X is good?" would be  meaningless.
(Premise 2) The question "Is it true that X is good?" is not meaningless (i.e. it is an open question).
(Conclusion) X is not (logically) equivalent to good.

This known as the open question argument as it depends on the second premise being an open question; that is a question whose answer has to be investigated rather than reasoned about. A closed question would be something like, Is that widow's husband dead? 

In response to criticism that the original argument assumed its own answer in the second premise G E Moore's original argument has been restated in the following manner.

(Premise 1) If X is good, then X will in itself motivate an individual to pursue it.
(Premise 2) A sane and rational speaker of English can understand that Action X* produces X, yet not pursue X*.
(Conclusion) X is not (analytically equivalent to) good.

The first premise follows Plato and Kant on the equvalence of knowledge of the good and right action. Hume would agree with premise 2 in that both belief and desire are needed to motivate actions.

In Our Time

This week's In Our Time, the 500th edition of the programme, is on free will and determinism and covers most of the topic in less than 45 minutes. You can download it as a podcast here or you can go to the programme's webpage and listen via the BBC I-Player here. Almost all of the programme's archive on culture, history, philosophy, religion and science is available to listen to. Search, for instance, for Socrates, or Good and Evil.