John Nolt on Moral Arguments

For those of you studying IB Philosophy, or taking Higher but interested in going beyond the simplicities of the course, John Nolt’s Environmental Ethics for the Long Term has an excellent section on philosophical arguments in ethics.

Section 2.2.1 has one of the best explanations of the “is/ought” fallacy I have ever read. Using the terms ‘prescriptive’ and ‘descriptive’ to refer to premises that respectively contain or do not contain a sentiment of something being right or wrong, he uses the phrase ‘prescriptive reasoning’ to refer to an argument where (at least) one premise and the conclusion include some sort of moral valuing.

Of course an argument can be valid and sound if it contains no moral sentiments (1), and one which has ‘moral’ or ‘ought’ premises might lead to a valid and ‘ought’ type conclusion (2).

Example 1:

all volvo cars have a steering wheel

my car is a volvo

therefore my car has a steering wheel


Example 2:

one should intervene when one person is abusing another against the latter’s will

‘abusing another against their will’ is what happens in sex-trafficking

therefore you should be acting against sex-trafficking

Of course one might object to the ‘truth’ of each of the premises here, but if one did agree with both then it would commit you to the conclusion. This is an example of what Nolt calls ‘prescriptive reasoning’. The problem is when someone tries to move from purely ‘descriptive’ premises to a prescriptive conclusion. This is the is/ought fallacy. The example used by Nolt is the use of Social Darwinism by the Nazis, simply because the ‘strong’ or ‘fittest’ survive it certainly does not follow that one should act in a way to make this happen.

Allowing this ‘prescriptive reasoning’ to stand is not the same as believing it to be sound. In fact it can be particularly difficult to spot problematic premises. Consider the following:

We ought to eliminate suffering.

The only feasible way to eliminate suffering is to eliminate all sentient beings.

Therefore we ought to eliminate all sentient beings.*

*Nolt, J Environmental Ethics for the Long Term (Abingdon: Routledge, 2015) 39.

‘begging’ the question

Firstly it probably helps to distinguish what philosophers mean by this slightly strange phrase when compared to something people say quite frequently that sounds very similar.

When someone says “that begs the question…” it usually means something like “well that makes me wonder about…”. For example:

Andy Murray only looks good on grass, which begs the question whether he can ever be ranked much higher than number 4 in the world…

Unfortunately for us, this doesn’t really have anything to do with what philosophers mean when they use these words together. When a philosopher suggests that a given argument is ‘begging the question’, they are claiming that it contains an assumption (probably implicit or hidden) in the premises that is necessary in arriving at the argument’s conclusion.

The Pan Dictionary of Philosophy defines ‘begging the question’ as

The procedure of taking for granted, in a statement or argument, precisely what is in dispute.

So an example might run something like this:

I know I am free. Whenever I have a tough decision to make I sit down, think about my options and opt for one on the courses of action.

This might not be the best example, but if we sort it all out it begins to look like this:

1. I make reasoned decisions.

C: These decisions are free.


But really what is happening here, is a bit more like this:

1. I make reasoned decisions.

2(implied). The fact I have this experience of weighing up options mean my decisions are free.

C: These decisions are free.

Now of course, 2 is exactly what philosophers would be looking to challenge if they were disputing that our writer has free will so, this is begging the question.