The ruling on donating an organ while alive or after death

Question:
Is it permissible for a Muslim person, whether alive or dead, to donate any organ of his body, whether to a person like him who needs that organ, such as a kidney for a good cause, or to a research center to conduct experiments on his body after his death, or to grant them free disposal of his organs after his death, meaning as a service to medicine?

Answer:
There is a difference of opinion among the scholars regarding this. There is a difference of opinion among the scholars regarding the donation of a kidney, and the like. Some of them permitted it, and some of them prohibited it.
As for his donating his body to be dissected, that is not permissible. He has no right to permit that. A Muslim is not to be dissected. The difference of opinion is only regarding whether it is permissible for him to allow his kidney to be taken for another, or his heart to be taken for another, upon his death?
This is a matter for consideration, and many of the scholars prohibit it. They say: He has no right to dispose of his body, for it belongs to Allah, and it does not belong to himself. So he has no right to dispose of himself, or his kidney, or his heart, or so on. Others said: If he permits it during his lifetime, then there is no harm. And I am hesitant in this matter. The discussion on this is well known among the scholars.