A man in a vegetative state would want to be revived, due to his Muslim faith, if his condition deteriorated, his family has argued in court.
They are in dispute with Pennine Acute Hospitals trust, which does not want to revive the 55-year-old if he worsens.
Doctors say resuscitation would not be in the best interests of Patient L.
In a statement, one of his sons said, under Islam generally, "we believe that you prolong life... and that you actively take every step to so do".
'Prolongation of death'
At the Court of Protection, at the High Court in London, he added: "My father was very aware of these issues and often when we heard stories in the media about negligence and decisions to turn off life support, he would wince his face and give a look of disapproval."
Claire Watson, appearing for the trust, said it was the unanimous view of clinicians and independent experts that the patient, from Greater Manchester, was in a persistent vegetative state.
She said his physical condition would deteriorate over time and he would develop wasting, skin sores and muscle tightening which would cause pain if he is capable of feeling.
The patient, who cannot be identified for legal reasons, has "minimal prospects of improving any neurological function and no meaningful prospect of further recovery", the court was told.
"Rather than there being the prolongation of life, there would be the prolongation of death and lack of dignity," Ms Watson added.
Patient L suffered severe brain damage following a third cardiac arrest in mid-July and relatives say it is too early to determine whether he is in a "permanent" vegetative state, arguing they have observed "some degree of responsiveness".
'Very close family'
A Do Not Resuscitate notice was placed in his notes without consulting the family in contravention of the trust's own policy, the court heard, and it was later taken out following objections.
Patient L's wife said in a written statement they were "a very close family", describing her husband of 40 years as a "happy, loving person and a loving and caring father".
The family have asked the judge to rule that "all steps" should be taken to preserve patient L's life.
The case continues.