The Fundamentals of Ethics

In Chapter 6, Shafer-Landau analyzes the natural law theory, which observes that animals lead fuller lives when their nature is fulfilled. Human beings are animals, too, and therefore the more they act according to their true nature, the better they are. Natural law theory is compelling because it addresses four fundamental questions in ethics.

To start, natural law theory offers an avenue to explore moral standards as entirely objective. This is often true of natural law theorists who are also theists and believe in a defined God-given human nature. This is the viewpoint of St. Thomas Aquinas, who argued that people are morally obligated to fulfill their nature as endowed by God (77).

Second, natural law theory clearly delineates its target audience: humans. Unlike other living organisms, humans are capable of sophisticated reasoning and rational thought. Therefore, they are moral agents and must uphold a certain degree of responsibility for their actions. This is why moral standards are not to be extended to animals or inanimate objects.

Third, natural law theory can pinpoint the origins of morality: They align perfectly with the existence of humanity. This is because human nature cannot exist without humans.

Finally, natural law theory has a clear answer to a fundamental problem in ethics: “how to gain moral knowledge” (78). Scottish philosopher David Hume famously articulated the following argument for moral skepticism: Knowledge comes from either conceptual or empirical truths; moral claims are neither conceptual or empirical; thus there is no moral knowledge to be gained. Conceptual truths are known through logic. For example, it can be said with certainty that squares are not triangles and all bachelors are men who have not yet wedded. Moral claims are not conceptual because even if we understand them, we can never truly know if they are true. Empirical truths are known through our five senses or our past experiences. For example, World War II ended in 1945 in America. Moral claims are not empirical truths because there is no way to experience them through our senses and no scientific instrument will reveal the world’s moral features.

According to natural law theory, however, there is a way to reject Hume’s critique. By finding a way to define human nature and then learning how to fulfill it, humans gain empirical knowledge about morality. Since scientists can study and define the nature of animals through behavioral observation, it is only logical they could do the same for humans as well. If human nature can be learned through observation, it is empirical knowledge; if human nature determines morality, then moral claims can be empirical as well.

What exactly is human nature? Shafer-Landau provides three theoretical answers, all of which are flawed. The first likens human nature to animal nature, given humans are animals as well. However, the limits of this theory are obvious: It is acceptable for animals to practice cannibalism or eat their children, and the same cannot be said of humans. The second theory posits human nature to be our most innate traits, the ones we inherit from birth. While this view may in theory address all of Hume’s criticisms, there is no consensus among philosophers as to what those innate traits are and how to differentiate them from acquired traits. For example, philosopher Jean-Jacques Rousseau believed in a human nature that is innately good, while Thomas Hobbes argued the opposite. Ultimately, Shafer-Landau points out that the origins of our impulses are irrelevant: They cannot be moral if they push us toward committing murder or rape (82). The final theory stipulates that human nature is a trait that all humans share. However, two problems persist: There may be no universal trait, and even if there were, it may not give appropriate moral guidance.

The final half of Chapter 6 offers two more theoretical attempts to delineate human nature. One takes shape in the theory of natural purposes, which stipulates that “human nature is what we are designed to be and to do” (83). This line of reasoning is sometimes defended by theists who believe God designed mankind and imbued them with purpose. However, the problem of the intelligent designer arises here, and its drawbacks are the same as with the divine command theory discussed in Chapter 5. There are also two secular attempts to define the human’s natural purpose. The first, titled the efficiency model, argues that humans’ purpose is to do tasks most efficient to them, the same way a heart’s purpose is to pump blood, since it is the best at that job. This stance is clearly problematic since humans are proficient in different tasks, a point that undermines the objectivity of the natural law theory. The second is called the fitness model, which presents fitness as the core of human nature. Species survival is a fight for the fittest to transmit their genes to their progeny, and therefore defenders of this model usually emphasize the importance of reproduction while condemning suicide and homosexuality. However, this line of moral reasoning is false: If fulfilling the natural purpose of procreation is always moral, then it should be acceptable for men to rape and impregnate as many women as they can. In sum, natural law theory differs from the rest by identifying human nature as an objective and absolute moral standard. However, without consensus on what qualifies human nature and how to convert it into a set of ethical codes, the theory can only provide a limited understanding of morality.

Chapter 7 explores the theory of psychological egoism. According to this viewpoint, all human motivation is spurred by self-interest, and altruism is a sham. Even acts of self-sacrifice are explained as ultimately selfish: The deepest motive that prompts such self-sacrifice might have been to alleviate guilt or to look good in front of others. In other words, all human actions are motivated by the desire to prevent personal loss or to gain personal benefit (or both) in the short or long term (or both) (94).

Psychological egoism is not an ethical theory but a psychological view. It ascribes self-interest as the most basic source of human motive, but it does not promote any moral standard to uphold. However, if true, psychological egoism can impact ethics by denying the existence of altruism and thus absolving people from having to act altruistically (for example, with kindness and compassion). This idea is summarized in the Implications of Egoism Argument, and the only way to challenge it is to prove psychological egoism wrong.

Shafer-Landau first explores two central arguments that attempt to uphold psychological egoism. The first is the “Argument from our Strongest Desires” (95). It claims that an individual’s actions are guided by their strongest desire, which is to pursue self-interest, and therefore all their actions are made with self-interest in mind. The biggest logical flaw with this line of reasoning is that it equates the pursuit of an individual’s strongest desire with the pursuit of self-interest. For example, if someone’s strongest desire is to help others at the cost of personal comfort and he sincerely admits this, this theory still insists the act is actually performed in pursuit of some hidden self-interested motive. Shafer-Landau likens this type of reasoning to conspiracy theories, which are irrational rather than logical. In sum, the argument from our strongest desires is flawed because it assumes the nonexistence of altruism rather than proves it: It falls into the “begging the question” fallacy.

The second approach to uphold psychological egoism is the “Argument from Expected Benefit” (98). It claims that individuals perform actions always with the expectation of being better off as a result. If they are better off, then they are promoting self-interest. Thus, all human actions are done with the goal of promoting self-interest. Once again, the second premise seems to assume the truth of the conclusion and falls into the begging the question fallacy. For example, people who enjoy volunteering might benefit from their actions, but this does not prove they are acting in self-interest. The enjoyment brought about by volunteering can easily be a foreseen benefit rather than the ultimate motive of their action.

In other words, to uphold their theory, egoists need to prove that altruism is a lie. There are two methods by which they attempt this. The first posits that all acts resembling altruism are motivated by the need to selfishly alleviate one’s guilty conscience. For example, an individual standing up to oppressive regimes is motivated by the desire to rest easy at the thought of having fought a terrible injustice. Shafer-Landau rebukes this: The existence of a guilty conscience is proof of someone’s capacity for care and empathy, traits that support rather than disprove the existence of altruism. The author points out that Eichmann slept well every night despite engineering the deaths of countless Jewish people in the concentration camps (100).

The second strategy that attempts to disprove altruism expands the realm of what is considered self-interest. A mother who dies to save her baby is still acting selfishly because she sees the baby’s welfare as her own. However, once again Shafer-Landau interprets this act as altruism: After all, a parent who is wholly self-centered does not care to extend that self-interest to account for their child’s misery.

Ultimately, psychological egoism attempts to understand human motivation, which can only be known through observation of behavior or personal testimony, neither of which are infallible. While psychological egoism might be valid, there are studies that increasingly suggest otherwise. For example, psychologist C. Daniel Baston’s “empathy-altruism hypothesis” repeatedly tested human response to empathy, and his conclusion strongly suggested that insight into others’ misery “can prompt altruistic motivation” (102-03). Although psychological egoism is highly unlikely to be true, according to Shafer-Landau, its validity is yet to be determined.