Here is a little thought experiment that should completely refute any residual notion that people are basically selfish, while it illustrates the case that desire fulfillment is what human action aims towards.
You, and somebody you care a great deal about (e.g., your child) have been captured by an evil extra-terrestrial mad scientist who is interested in conducting all sorts of experiments on humans. It offers you the following two options:
Option 1: “I will take this other person to another ship and perform all sorts of medical experiments on him. We have become well versed in the art of vivisection, I assure you, and the process will be painful and unending. However, you will be made to believe that your child has been set free and allowed to live a safe and happy life.”
Option 2: “I will let your child free with enough gold to live a healthy and happy life. However, you will be made to believe that I have taken your child to another ship and that I am performing all sorts of medical experiments on him. You will be made to believe that we have become well versed in the art of vivisection, and that the process will be painful and unending.”
Of course, I will also cause you to forget about this choice.
Which option do you choose?
The view that says that everyone is only after their own happiness would have to argue that everybody would select option 1. This is, after all, the option that provides the agent with the most happiness. However, this is contrary to fact. Most people go with option 2 — they sacrifice their own happiness for the sake of the child.
We have no actual experiments to point to that involve locking people in a cell and asking them to make this choice. So, maybe, they would all choose Option 1. But, most people at least report that they would not, and no reason can be provided to doubt them. The selfishness theory needs to at least explain why so few people think (incorrectly) that they would choose Option 2.
The widespread choice of Option 2 is easily explained if we hold that desires are dispositions to make or keep the proposition that is the object of the desire true. The parent with a desire that their child is healthy and happy is disposed to make or keep the proposition “my child is healthy and happy” true. Option 2 is the option in this case that makes or keeps the proposition true. It is desire fulfillment that we are after in life, not pleasure, nor happiness.
Interesting, right? I have no commentary to offer, except to say that if the experiment is to prove that “humans are basically unselfish”, as he claims, then it is most definitely incomplete.