<p>“A man with no family who is about to commit suicide shoots another man, steals his wallet and the groceries he’s carrying, and eats the food within the grocery bags as his last meal. He was simply too lazy to use his own money to buy food, so he killed a man and stole his food.”</p>
<p>…Your example does not make sense. How would a suicidal man be too lazy to buy food but not lazy enough to commit homicide? I would think the latter would not only be more difficult, but expend more energy, require more skill (marksmanship, etc.), a complete negation of morals, and the psychologically demented mindset of a sociopath. (A sociopath, by the way, would not be likely to commit suicide.) </p>
<p>“If every person on earth is killed but one, every act the remaining person does is purely selfish.”</p>
<p>So, if the last person alive buried his wife before he dies of a heart attack, is that a selfish act?</p>
<p>selfish
- devoted to or caring only for oneself; concerned primarily with one’s own interests, benefits, welfare, etc., regardless of others.
- characterized by or manifesting concern or care only for oneself: selfish motives.</p>
<p>And even if he ended up dying of old age, your statement is not necessarily true. You must first ask what reasons that person has for living.
He might want to stay alive to honor the memory of a loved one, or of mankind.
He might stay alive in order to accomplish something; for example, write a documentary in the hope that some extraterrestrial being will find it after he dies.
He might live in the hope to find another living human being. After all, how would he know he’s the only person left in the world?
He might stay alive because it’s against his religion to commit suicide.</p>
<p>In these instances, said “last man alive” is not concerned only for himself.
For any act that he did to be perfectly selfless, he would have to ONLY be concerned with himself. That rules out grieving for other people, or even thinking about other people while doing it (because at this point in the hypothetical catastrophe, others have absolutely nothing to do with him). </p>
<p>And it would never work, because he could never forget that he is alone.</p>