When I was 17 years old I had surgery because of a disease. The day after the surgery, I awoke to find a friend of mine sitting in a chair across from my bed. I don't remember much about his visit. But I will not forget that he visited me on that day, and sat there for I don't know how long, while I was under the influence of a morphine drip . We benefit greatly from our close friendships, but they are not a matter of calculable gain or loss. Our age, what we might call the age of economics, is strongly influenced by two types of relationships that reflect the lives we are encouraged to lead. There are consumer relationships, those that we participate in for the pleasure they bring us. They are focused on the present. It is what brings immediate pleasure that matters. And there are entrepreneurial relationships, those that we invest in, hoping they will bring us some return. Aristotle thought that there were three types of friendship: those of pleasure, those of usefulness, and true friendship. In pleasure friendships, he said, "It is not for their character that men love ready-witted people, but because they find them pleasant." About the usefulness friendships, he said, "Those who love each other for their utility do not love each other for themselves, but because of some good which they get from each other." Although we benefit from our close friendships, these friendships are not a matter of calculable gain and loss. Consumer pleasures are lasting for only a limited time. They surround us for a short period and then they fade, like a drug. Entrepreneur friendship, when successful, leads to the victory of personal gain. It is precisely this non-economic character that is threatened in a society in which each of us is offered only the choices of ownership, shopping, competition and growth. It is threatened when we are led to believe that friendships without obvious recognizable gain are, in the economic sense, irrational . Friendships are not without reason, perhaps, but they are certainly without that particular reason. Shared experience, not just everyday amusement or advancement, is the true basis of friendship. The author tries to persuade readers to accept his argument by   _  .
explaining three types of friendship discussing questions analyzing causes and effects providing examples and facts