| Conceivable action | Conceivable response to | Description |
| Termination of physical functions, with respectful attention to the body | Brain death: A brain dead "human being" is already medically deceased. | A terminates support for remaining physical functions of B, who is already medically dead. |
| Involuntary passive euthanasia (allowing to die Type 1) |
Persistent vegetative state (PVS); terminal illness; physically incapacitating illness of great length with no chance of significant recovery | A allows B, who is medically alive, to die: Extraordinary efforts to preserve life are avoided in spite of prior expressions by B to the contrary.2 |
| Nonvoluntary passive euthanasia (allowing to die Type 2) |
PVS; terminal illness; certain cases involving infants, children, and severely retarded | A allows B, who is at least medically alive, to die: extraordinary efforts to preserve life are abandoned although B cannot give or withhold consent.2 |
| Voluntary passive euthanasia (allowing to die Type 3) |
PVS with an advance directive; terminal illness; physically incapacitating illness of great length with no chance of substantial recovery | A allows B, who is at least medically alive, to die: Extraordinary efforts to preserve life are abandoned with B's consent.2 |
| Involuntary active euthanasia | PVS; terminal illness; physically incapacitating illness of great length with no chance of substantial recovery | A kills B contrary to B's probable or stated will.2 |
| Nonvoluntary active euthanasia | PVS; terminal illness; physically incapacitating illness of great length with no chance of substantial recovery | A kills B without B's request but not arguably contrary to it.2 |
| Voluntary active euthanasia | Request of person suffering extreme pain or anticipating an undignified end | A kills B at B's request.2 |
| Assisted suicide | Request of person suffering extreme pain or anticipating an undignified end | A helps B kill B at B's request.2 |
| (Unassisted) suicide | On balance, taking one's own life seems able to produce a great good or avert a great evil. | A intentionally kills A. |
2. All forms of euthanasia, to be euthanasia at all, must be primarily motivated by a desire to end the patient's suffering or indignity or, in the case of PVS, "pointless vegetative existence." Assisted suicide that is defended in this context would have to be similarly motivated. If people are "euthanized" just to get rid of them or primarily because caring for them is costly, this is not strictly speaking euthanasia even if that is what it is publicly called. Judith Boss includes physician assisted suicide in the category of voluntary active euthanasia (Judith Boss, Analyzing Moral Issues, fifth edition [New York: McGraw-Hill, 2010], chart on p. 178); in spite of the similarities between these actions and in a number of the moral issues they raise, they are distinct, and some of the moral issues they involve differ.