Let me paint out a plausible scenario!

The year is 2245. One day Adam is at his local convenience store and he discovers a new flavor of juice. Of course he buys it because he likes to live on the wild side. Before drinking the juice, he reads the label and it reads:

“Upon consumption, there is a moderate chance that a second conscious head will grow out of your shoulders”

Adam weighs the risk and reward and comes to the conclusion that it’s worth it to drink the juice. Sure enough, when he wakes up the next morning, he finds that the second head did in fact grow out of his shoulders. The head is clearly conscious. It can talk and even has its own dreams and aspirations.

When Adam goes to the hospital, the doctor tells him that the head will need to feed off of the nutrients in Adam’s body for 4-5 months, or else it will die. As of now, the head can't control anything but his own head. It's just waiting for a few months to get stronger and go on its own life. After those 4-5 months, the head will grow strong enough to remove itself from Adam and grow its own body to live on its own. Furthermore, when the head does detach itself, Adam’s body will go perfectly back to normal. 

Adam’s life is not majorly affected by this new head. He can still do most physical activities without much stress. He just has to buy extra food and he can’t sleep on his side. His boss can’t fire him either, because it’s against company policy. But still, Adam doesn’t want this head to be living on his shoulder! It's his damn shoulder! Adam would prefer to chop off the area around his shoulder, detaching the head. Technically, Adam says, it’s his body and he can do whatever the hell he wants to it! If the head happens to die, that’s not his problem.

So, should Adam be able to chop off this head if he wants to!?

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Important things to know (tl:dr):

• Adam knowingly caused the head to grow when he drank that juice.
• The head is conscious and even has dreams and aspirations.
• The head needs to live off Adam's body and nutrients for 4-5 months.
• After those months, it will branch off and form its own body.
• If Adam detaches the head before the head is ready, the head will die.
• When the head leaves (or is chopped off), Adam's body will go completely back to normal.
• Adam's job cannot fire him for this head.
• The new head cannot control the body.

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What do you think should be legal? Should a person be legally allowed to remove a head that’s growing on their body? Or would that be murder?

What would you want do? Would you want to chop off the head? Or would you want to let it live and have its own life?

http://en.wikipedia.org/wiki/A_Defense_of_Abortion he sort of butchered the actual argument, here is the more sound verrsion.