Recognising and applying principles

Arguments which rely on general principles have implications beyond their own subject
matter, because it is in the nature of a general principle that it is applicable to more than
one case. A piece of reasoning may use such a principle without explicitly describing it as a
general principle, so we need to be alert to the fact that some of the statements in an
argument may apply to cases other than the one under discussion. There can be many
kinds of principle, for example, legal rules, moral guidelines, business practices, and so on.
Principles may function in an argument as reasons, as conclusions or as unstated assumptions.
So, when we are going through the usual process of identifying reasons, conclusions
and assumptions, we should ask ourselves whether any of them is a statement with general
applicability.
The skill of identifying principles is valuable, because sometimes the application of a
principle to other cases – that is to say, the further implications of a principle – may show
us that the principle needs to be modified, or maybe even rejected. Suppose, for example,
someone wants to argue against the use of capital punishment, and offers as a reason
‘Killing is wrong’. This principle, stated as it is without any qualification, obviously has
very wide applicability. It applies to all cases of killing. So, if we are to accept it as a
principle to guide our actions, it means that killing in wartime is wrong, and killing in selfdefence
is wrong. If we are convinced that killing in self-defence cannot be wrong, then we
have to modify our original principle in order to take account of exceptions to it. Applying
principles involves being consistent in our reasoning, recognising all the implications of
our own and others’ reasoning.
Another example is offered by a debate in the sphere of medical ethics. It has been
suggested that when the demand for treatment for illness exceeds the resources available,
and thus decisions have to be made about priorities, one type of illness which should come
very low on the list of priorities for treatment is illness which individuals brings upon
themselves by their actions or lifestyles. Such illness can be described as ‘self-inflicted’.
Most doctors would not take the view that self-inflicted illness should not be treated, but it
is an issue which is often mentioned when public opinion is consulted about how best to
use the resources available for health care. For example, someone may say, ‘We should not
give high priority to expensive heart treatments for smokers, because they have brought
their illness on themselves’.
Clearly the principle underlying this is that ‘We should not give high priority to the
treatment of self-inflicted illness’, and it is a principle with wider applicability. But in order
to understand to which cases of illness it properly applies, we need to be clearer about
what exactly is meant by ‘self-inflicted illness’. At the very least it must mean an illness
which has been caused by the actions or behaviour of the person who is ill. On this
definition, the principle would apply to a very wide range of illnesses – for example,
smoking related diseases, alcohol and drug related diseases, diseases caused by unsuitable
diet, some sports injuries, some road accident injuries, some cases of sexually transmitted
disease. However, it may be claimed that one cannot properly be said to have inflicted a
disease on oneself unless one knew that the action or behaviour would cause the illness, or
it may be claimed that a disease cannot properly be said to be self-inflicted, if the action
which caused the disease was carried out under some kind of compulsion or addiction.
So, perhaps one would wish to modify the definition of ‘self-inflicted illness’ to read, ‘an
illness which has knowingly been caused by the deliberate and free action of an individual’.
This definition would give the principle narrower applicability. For example, it would not
be applicable to diseases caused by bad diet when the individual did not know the effects
of a bad diet. Nor would it apply to cases of illness caused by addiction. But we may still
find that those cases to which it did apply – for example, a motor-cyclist injured in a road
accident through not wearing a crash helmet – suggested to us that there was something
wrong with the principle.
Applying and evaluating principles
For each of the following principles, think of a case to which it applies, and consider
whether this particular application suggests to you that the principle should be modified
or abandoned. This exercise would work well as the basis for a class discussion.
1 No one should have to subsidise, through taxation, services which they themselves
never use.
2 We should not have laws to prevent people from harming themselves, provided their
actions do not harm others.
3 There should be absolute freedom for the newspapers to publish anything they wish.
4 Doctors should be completely honest with their patients.
5 You should never pass on information which you have promised to keep secret.