A member of the studio audience has asked me a question that I would like to answer as a way of illustrating how some of the principles of desire utilitarianism can be employed.
Maybe you have said this before, but I am just wondering why you think it important to safeguard the survival of the human species?
Technically, it is not the species per se, since theories suggest that, if life continues, at least some of our descendents will not qualify as the same species. But they are still our descendants. If we are going to talk about the value of continuing the human race, we should start with the nature of value in general.
Value exists in the form of relationships between states of affairs and desires. In order to figure out the value of the survival of the human race, we must look at which states of affairs would be true in a world in which humans did not exist, and whether those propositions are the propositions of any desires. This is to be compared to what is true of a universe in which humans do exist, and whether those propositions are the objects of any desires.
In order to determine moral value, we have to ask another set of questions. We have asked whether the propositions that are true in various states are propositions that are the objects of various desires. However, to answer questions about moral value, we have to ask whether those desires themselves are malleable and, of so, whether they are desires that tend to fulfill or to thwart other desires.
If a malleable desire is a desire that tends to thwart other desires, then this is a bad (evil) desire that people generally have reason to inhibit. If a malleable desire is a desire that tends to fulfill other desires, then this is a desire that people generally have reason to promote.
This means that if a state in which no humans exist tends to fulfill certain desires, but those are desires that people generally have reason to inhibit, then people generally have reason to condemn those who have such desires. They have reason to call such people evil and to act so as to prevent people generally from adopting those desires that they have reason to condemn.
A person who might express an interest in seeing the human race become extinct probably has one of two sets of attitudes.
Perhaps he desires a state in which humans do not exist. In this case, the individual has a desire which, in one sense, is no different than a desire to have sex, or the desire to kill a small furry animal, or a desire to watch a sunset. This is simply something that this agent liks.
In this case, we then ask whether the desire for a universe without humans is a malleable desire and, if so, whether it is a desire people generally have a reason to promote or to inhibit. Is this desire for the extermination of the human race like the desire to save a child from pain and suffering, or is it like a desire to inflict pain and suffering on a child?
I am going to wager that more people have more and stronger desires that will be fulfilled by the continuation of the human race than that will be thwarted by the survival of the human race. In other words, people generally have more and stronger reason to condemn such a person than to praise him – to promote fewer cases of people having such a desire and weaker instances where the desire occurs.
Or, in other words, those who desire the extermination of the human race are not good people.
We could ask how the desires of animals fit into this. Would the desires of animals be better fulfilled by our extinction, or less well fulfilled?
One could argue that the animals that we eat and otherwise kill because they are useful to us have reason to see humans extinct. However, life in a state of nature is no picnic. Starvation, disease, predators, accidental injuries, parasites, and the pain of old age are a part of the everyday life of animals. Those who are our pets tend to enjoy a far better life than those who live in the wild. Even many of the animals we harvest are protected from predators and disease and kept from hours or days of suffering if they become sick or injured. Ultimately, many would have good reason to argue against human extinction if they could, and few have reason to argue for it.
The other combination of attitudes that might explain an expressed interest in human extinction would be a desire to realize that which has intrinsic value, and a belief that untouched nature is intrinsically good. Even though the animals suffer at least they suffer a ‘natural’ illness, injury, or death – and such things are somehow good.
No action can realize anything of intrinsic value because there is no intrinsic value to be realized by any action. One can no more realize a state of intrinsic value than one can, by thought alone, teleport people out of a burning building.
So, does a state in which humans have become extinct have value?
In terms of real value – the type that is real – it almost certainly does have value. Many of our strong and stable desires suggest that the desire to preserve the species is a desire that people generally, and even many non-human mammals, have many and strong reasons to promote.