The Meaning and Purpose of Life in Twenty Natural Desires

To the question of the meaning and purpose of human life, the best answer--the answer we all give by the way we live our lives--is that we find the meaning and purpose of our lives in striving for the fullest satisfaction of our natural desires.  Evolutionary science helps to explain why we are moved by the twenty natural desires of our evolved human nature.  That scientific explanation is supported by lots of evidence.  One of the best general surveys of that evidence is Stephen Sanderson's Human Nature and the Evolution of Society (Westview Press, 2014).

Some of what Sanderson says, however, seems to deny that science can teach us anything about the meaning and purpose of life.  First of all, he warns against the naturalistic fallacy in inferring anything about moral values from natural facts.  And, secondly, he dismisses teleological thinking about the ultimate purpose of life as mistaken.  But implicit in Sanderson's writing is the recognition that we can rightly infer moral values from functional facts, and that even if we cannot find any cosmic purpose for life, we can find the immanent purpose of life inherent in our natural human desires.

After explaining the naturally evolved differences in the propensities and abilities of men and women, so that men on average are less inclined than are women to certain kinds of activities, Sanderson warns against the assumption that such natural tendencies tell us anything about what men and women should do.  This is the naturalistic fallacy:  deriving an "ought" from and "is."  One cannot infer a moral judgment from a purely descriptive statement about how human beings behave.  If men are naturally inclined towards careers such as firefighting, and women are naturally inclined towards careers such as nursing, it does not follow logically that men should be firefighters, or that women should be nurses (238).

And yet Sanderson seems to contradict himself in his writing about scientific research when he uses value-laden language--such as judging some behavior as "dysfunctional"--which seems to commit the naturalistic fallacy.  For example, when he reports Harry Harlow's famous experiments with young monkeys reared by artificial mothers made of wire rather than real mothers.  The monkeys exposed only to artificial mothers showed "severe emotional disturbance" and "dysfunctional" behavior, comparable to what happens to human children reared in orphanages without any maternal care (192-95, 210).

More generally, Sanderson concludes his book by arguing that evolutionary science can give an answer to the question of the meaning of life.  "The meaning of human existence is to achieve satisfaction with respect to the basic goals and desires that are part of human nature.  Since in real life these goals and desires are often in conflict, they must be harmonized or balanced in some way" (382).  He then offers a slightly modified version of my list of twenty natural desires.

And while Sanderson rejects any teleological belief in "some deep cosmic purpose embedded in the universe or, more likely, in the mind of God," he does see a purpose embedded in the desires of human nature: "If there is no ultimate purpose to our lives, life is emptied of all meaning.  Why then bother to live at all? The reason to bother is to fulfill the desires that emanate from our species-specific human nature.  This is sufficient.  There doesn't need to be anything else for life to be meaningful" (383, 386).

I agree.  Even if science cannot support a cosmic teleology of purposes set by a Cosmic God, Cosmic Nature, or Cosmic Reason, science can support an immanent teleology of purposes set by human nature, human culture, and human individuals, by which human nature and human culture constrain but do not determine the purposes set by human individuals in deciding how best to rank and harmonize their natural desires over a whole life well lived.

And so, for example, we can judge that children deprived of parental care are likely to show "dysfunctional" behavior because it is hard for children to become happy adults if their natural need for parental care has not been satisfied.

In this way, a natural science of human nature can support moral judgments through the hypothetical imperatives of given-if-then reasoning: given the evolved human nature of our desires, if we want to live desirable lives, then we must live in ways that are most likely to satisfy those desires.

Some of my posts on these points can be found here, here, here., here., and here.