I have heard that there is a consensus on the equivalence of the
actions of withholding medical treatment and
withdrawing it, even when the withdrawal requires a positive
action from the medical professional (e.g., disconnecting a
machine).
Here is a reason to doubt this consensus.
Consider first this pair of cases. In both, the following facts hold.
A patient will die within hours without a ventilator, and competently
requests that they be on a ventilator. However, an enemy of the patient
has very credibly threatened the doctor with death if the patient is on
a ventilator tomorrow. The only way the enemy can get at the patient is
through the doctor, and there is no way to protect the doctor from the
enemy. The difference between the two cases, however, is that in one
case, the patient is already on a ventilator and in the other the
patient is not yet on it.
If the patient is already on the ventilator, the doctor should refuse
to disconnect the patient because of the enemy’s threat. Disconnecting
the patient would be a wrongful cooperation in murder, and one should
die rather than do that. Disconnecting the patient would be tantamount
to murder. On the other hand, if the patient is not yet on the
ventilator, then it would be supererogatory for the doctor to ventilate
the patient at the expense of the doctor’s life. The doctor does not
have the duty to save the patient’s life at the nearly certain expense
of their own life. And even if one thinks it is a duty, failure
in this duty is far below the wickedness of murder.
But disconnecting is withdrawal and failure to connect is
withholding. Thus the two are not equivalent actions, because they can
differ in moral evaluation even when done for the same reason (avoidance
of the threat).
One might think the two become equivalent when the patient
refuses to consent to the treatment (whether its continuation or
initiation). It seems odd to think that the patient’s refusal somehow
turns both actions equivalent.
But anyway, consider a reversal of the threat case. A “friend” of the
refusing patient informs the doctor that they will cut off the doctor’s
thumbs unless the patient is on a ventilator tomorrow, and
suppose that the ventilation in question is invasive. It seems pretty
plausible that in the case where the patient is not yet on the
ventilator, the doctor should refuse to invasively ventilate them. For
to invasively ventilate the patient would be an assault on the patient’s
bodily integrity, and one should suffer a greater loss to one’s own
bodily integrity rather than impose a lesser loss on another.
But in the case where the patient is already on the
ventilator, it seems that the doctor has no obligation to suffer a
greater loss themselves in order to respect the patient’s wish to be
disconnected from the ventilator.
Thus, even in the case where the patient refuses consent, withholding
and withdrawing are not equivalent.