We might as well begin by being honest as to fact; it has always been human practice to commit suicide, in the opinion that life is not worth continuing; it has also been customary to kill people mercifully - including for this purpose pre-people (foetuses) and post-people (the terminally detached from meaningful life).

There is not the smallest point in pretending that moral uplift campaigns, or the guilt feelings they often generate, will alter this state of affairs. The only reasonable, and possibly useful, response to it is to consider whether it can be regularised and controlled for the betterment of human life.

In short, practical ethical inquiry cuts more ice than moralising from a great height. To make such inquiry productive, we have to begin from where we're at.

These preliminary observations apply in many areas of concern but this article is narrowed down to consideration of voluntary euthanasia, primarily; the involuntary and 'by proxy' aspects of 'mercy killing' cannot, however, be avoided entirely.

Voluntary euthanasia is a very personal matter and therefore I make no apology for the title of this article being in the first person. That personal element is the reason for the word voluntary.

I am against ending my days living other than the good life and so 'the good life' must be defined for, if I am living it now, then it would be destructive for me to kill myself now merely to make sure that I do not end my days in the manner I would wish not to.

Bertrand Russell said that the good life is "one that is informed by knowledge and inspired by love" - or some such words. This is acceptable to me as a definition but I think it needs strengthening. I would add to Russell's definition of the good life: I would say that it is one that is "one that is informed by knowledge and inspired by love and restrained by respect for the autonomy of others". One could argue that my third clause only underlines Russell's second one but perhaps a little underlining is no bad thing in this connection.

It could be said that the good life is, alternatively, describable as one in which there is sufficiently full 'give and take' between oneself and one's fellows. On that somewhat simpler definition, I do not wish to continue to live when I am only a 'taker' .... when all or most all of the following are true of me - and terminally so .... 1) great and more or less continuous pain; 2) inability to convey food and drink to my mouth; 3) double incontinence; 4) inability dependably to recognise people whom I have known and cared about for years; 5) inability to listen and to speak reasonably articulately; 6) inability significantly to exercise many of the preferences that normally I might have exercised.

I have seen people in such predicaments and I assert that their survival, in such a manner, is a horrific insult to their true selves and that to inflict survival in such circumstances is nothing less than assault against the person. I want none of it for myself. I will knowingly inflict none of it on others.

To be in such a pitiful state is not to live 'the good life'; it is a cessation of one's ability to 'give' while it is a continuation of 'taking' - but for no good purpose. The only, perverted purpose that survival under those conditions serves is to enable insensitive 'caring' enthusiasts to reassure themselves as to how 'caring' they are. I do not wish to be an offering upon the altar of anyone's self-indulgence.

So I am fully persuaded that 7) living wills should be respected : 8) that there should be provision for the appointment of proxies to take life and death decisions on one's behalf in the event of one's own terminal incapacity : 9) that, in the event of properly drawn up living wills and the proper appointment of such proxies, those proxies should be exempted from the provisions of laws forbidding 'assisted suicide'. 10) I also favour the legal protection of doctors, acting on the authority of the patient or proxy, from legal action against the practice of 'constructive neglect' and action that can have the 'double effect' of killing pain and hastening the death of (killing) the terminal patient.

All the above can come under the umbrella term 'voluntary' if the arrangements for living wills and proxies are properly in place. But we also have to face the fact that there are occasions, terrible emergency occasions, when the practice of 'mercy killing' can be morally acceptable (and the shirking of mercy killing can be morally reprehensible).

If I were alone with someone trapped by earthquake debris and with no hope of rescue I would certainly think it right for that companion to kill me if I were dying in great pain from obviously terminal injuries. In the event of my not having made a living will and not having nominated proxies, killing me, although not, officially, voluntary euthanasia, would not, in my view, be morally reprehensible; shirking that act would be.