When someone is experiencing life-threatening illness or injury, ethical questions about the preservation of life often arise. What kinds of treatments are worth trying? Is it okay to refuse possible life-saving measures? When is enough enough? When considering these kinds of questions, the Church invites us to distinguish between “ordinary” means of preserving life and “extraordinary” means of preserving life. Ordinary means of preserving life are morally obligatory because deliberately refusing to provide ordinary life-sustaining necessities amounts either to murder or suicide. Extraordinary means are life-preserving measures that one can legitimately decline without willing one’s own death or the death of the person in one’s care. But how can we tell the difference in practice? How can we determine whether some potentially life-preserving measure is ordinary or extraordinary? To begin to answer those questions, let us consider a passage from the Catechism of the Catholic Church:

Discontinuing medical procedures that are burdensome, dangerous, extraordinary, or disproportionate to the expected outcome can be legitimate; it is the refusal of ‘over-zealous’ treatment. Here one does not will to cause death; one’s inability to impede it is merely accepted. (CCC 2278)

The catechism uses “extraordinary” as one of four terms to describe medical procedures that may rightly be refused. Each of the four terms has an opposite. “Extraordinary” is opposed to “ordinary,” “burdensome” opposed to “beneficial,” “dangerous” opposed to “safe,” and “disproportionate” opposed to “proportionate.” When we think about life-sustaining measures in these terms, we can learn how to identify which measures are extraordinary and which are ordinary.

The term “burdensome” refers to the negative effects of a particular measure or procedure. A procedure imposes burdens when it produces undesirable outcomes. Chemotherapy, for example, can produce negative outcomes like nausea, reduced energy, hair loss, and weakened immunity. These undesirable effects are considered burdens especially when they are experienced in the present. When they are anticipated as outcomes foreseeable in the future, they might be called dangers or risks. The opposite of “burdensome” is “beneficial.” Benefits designate positive effects of a procedure; the good outcomes it brings about in the present as well as the positive results it is likely to effect in the future. The term “safe” has less to do with positive effects but denotes a relative lack of negative effects.

For the sake of clarity, we can use the term “burdens” to include all the negative effects of a procedure and “benefits” to include all positive effects, whether experienced in the present or anticipated in the future. The terms “dangerous” and “safe” can therefore be absorbed into a broad understanding of burdens and benefits.

Let us again consider the example of chemotherapy. We have already listed some of the possible burdens. The benefits of chemotherapy would be the whole or partial destruction of cancerous tumors. Now there are different kinds of chemotherapy and the effects of chemotherapy will be different in different circumstances. Even more variable is the extent to which the effects of chemotherapy will be both burdensome and beneficial to a particular patient. If the patient is strong and otherwise healthy and the cancer is treatable, the possible negative effects of nausea, weakness, and reduced immunity may be minimally burdensome and the possible life-saving effect might be enormously beneficial. On the other hand, if the patient is frail and has other health problems, the negative effects of chemotherapy might impose unthinkable burdens, while the positive effect may be of minimal or no benefit.

We can now consider the application of the terms “proportionate” and “disproportionate.” The proportion to be considered is the proportion between burdens and benefits. In the words of the Catechism, a procedure is “disproportionate to expected outcomes” when the beneficial outcomes that can reasonably be expected are outweighed by the burdens the procedure is likely to impose. This could be the case for the frail, sickly person considering chemotherapy. In his case, the benefits of chemotherapy might be considered disproportionate to the heavy burdens that treatment would impose.

In cases like this, when the benefits of a potentially life-sustaining procedure are disproportionate to its burdens, the procedure is determined to be an extraordinary means of preserving human life. Therefore, by declining or discontinuing that procedure, “one does not will to cause death; one’s inability to impede it is merely accepted.”