The core evil of euthanasia is that an individual or group of people think they have the right to put someone else to death. "Killing a human being" is not a very nice concept. To make it more acceptable, therefore some people start playing with the language. They say, for example, that the one who is incurably ill or comatose is a "vegetable". A vegetable? What kind? A cucumber? Carrot? NO MATTER WHAT THE AILMENT HE/SHE SUFFERS FROM, A HUMAN BEING IS ALWAYS HUMAN, AND ALWAYS HAS A RIGHT TO LIFE WHICH NOBODY, OF ANY PHILOSOPHICAL, POLITICAL, OR RELIGIOUS PERSUASION EVER IS ABLE TO TAKE AWAY. In fact, it is precisely when life is afflicted by weakness and illness that it is all the MORE deserving of our care. Remember the song, "He Ain't Heavy; He's My Brother". Advocates of euthanasia do not see the ill this way, but only as a burden. God forgive them. And how about you? 6
Physician assisted dying is morally and theologically impermissible because of God’s sovereignty and the sanctity of human life. “Death is seen as evil in itself, and symbolic of all those forces which oppose God-given life and its fulfillment. Salvation and redemption are normally understood in Eastern Christianity in terms of sharing in Jesus Christ’s victory over death, sin and evil through His crucifixion and His resurrection. The Orthodox Church has a very strong pro-life stand which in part expresses itself in opposition to doctrinaire advocacy of euthanasia.”
Non - religious
Tony Nicklinson suffered a stroke at the age of 51 that left him paralysed but his mind completely fine.
What the two slippery slopes have in common is that it is cheaper and easier for a society to kill people who are retarded or in severe pain than to provide the proper care for them. Legalising euthanasia promotes a culture where killing people is a viable option.
The existing legal restrictions leave both the incurable patients as well as pro-euthanasia activists helpless who approve euthanasia as a goodwill gesture for a patient's dignity.
Opposition to euthanasia also comes from Muslim teachings; 'When their
time comes they cannot delay it for a single hour, nor can they bring
it forward by a single hour' (Qur'an 16.61), translated as, only Allah
can choose the length of life a person has.
Oddly enough, the law of universalisability allows for there to be exceptions - as long as the exceptions are themselves universalisable. So you could have a universal rule allowing voluntary euthanasia and universalise an exception for people who were less than 18 years old.
It should be acknowledged that these conditions are quite restrictive,indeed more restrictive than some would think appropriate. Inparticular, the first condition restricts access to voluntaryeuthanasia to those who are terminally ill. While thatexpression is not free of all ambiguity, for present purposes it canbe agreed that it does not include victims of accidents who arerendered quadriplegics, sufferers from motor neurone disease, orindividuals who succumb to forms of dementia like Alzheimer's Disease,to say nothing of those afflicted by 'existential suffering'. Thosewho consider that cases like these show the first condition to be toorestrictive (e.g., Sumner 2011; Varelius 2014) may, nonetheless, agreethat including them as candidates for legalized voluntary euthanasiawould make it far harder in many jurisdictions to gain sufficientsupport for legalization (and so make it harder to help thoseterminally ill persons who wish to die). Even so, they believe thateuthanasia should be permitted for those who consider their lives nolonger worth living, not just for for the terminally ill. The fifthcondition further restricts access to voluntary euthanasia byexcluding those capable of ending their own lives, and so may bethought unduly restrictive by those who would wish to discourageterminally ill patients from attempting suicide. There will be yetothers who consider this condition to be too restrictive becausecompetent patients can always refuse nutrition and hydration. (Whilethis is true, many competent dying persons still wish to have accessto legalized medically assisted death, rather than having to rely onrefusing nutrition and hydration, so as to retain control over thetiming of their deaths, and to avoid needlessly prolonging the processof dying.)
The term euthanasia is derived from the Greek word for "good death" and originally referred to as “intentional killing” ( Patelarou, Vardavas, Fioraki, Alegakis, Dafermou, & Ntzilepi, 2009).
The third condition recognises what many who oppose the legalizationof voluntary euthanasia do not, namely, that it is not only a desireto be released from pain that leads people to request help withdying. In The Netherlands, for example, pain has been found to be a lesssignificant reason for requesting assistance with dying than otherforms of suffering, including frustration over loss ofindependence. Sufferers from some terminal conditions may have theirpain relieved but have to endure side effects that, for them, makelife unbearable. Others may not have to cope with pain but instead beincapable of living without forms of life support that simultaneouslyrob their lives of quality (as with, e.g., motor neurone disease).
If a person wants to be allowed to commit euthanasia, it would clearly be inconsistent for them to say that they didn't think it should be allowed for other people.
From a utilitarian viewpoint, justifying euthanasia is a question of showing that allowing people to have a good death, at a time of their own choosing, will make them happier than the pain from their illness, the loss of dignity and the distress of anticipating a slow, painful death. Someone who wants euthanasia will have already made this comparison for themselves.