Consider a consequentialist view according to which each individual counts for one in virtue of having a capacity for a meaningful life (cf.
Afterward, it considers texts that provide answers to the more substantive question about the nature of meaning as a property.
Some accounts of what make life meaningful provide particular ways to do so, e.g., by making certain achievements (James 2005), developing moral character (Thomas 2005), or learning from relationships with family members (Velleman 2005).
First, to ask whether someone's life is meaningful is not one and the same as asking whether her life is happy or pleasant.
A life in an experience or virtual reality machine could conceivably be happy but very few take it to be a prima facie candidate for meaningfulness (Nozick 1974: 42–45).