It does not dictate equal treatment of all interests, in the belief that different interests guarantee different treatment (Singer 26). Human beings, therefore, give significant interests priority over minor interests. Apart from justifying different treatment for different interests, this principle calls for different treatment of the same interest where diminishing marginal utility is a factor.
This philosophy of Singer requires the concept of impartiality while comparing interests. Singer asserts that a person’s interests must always be weighed according to the person’s existing properties. The major interests in human beings are those that satisfy the basic need for food and shelter, develop one’s abilities, avoid pain, and enjoy warm personal relationships and those that allow a person to pursue his or her project without interference. These major interests entitle a person to equal consideration in the capacity of happiness and suffering. Singer’s approach favors a model of life where he measures the minor interest from their wrongness of frustrating the goals of life. Singer argues that eating of animals and using them for scientific research is morally indefensible (Singer 48). From his perspective, like human beings, animals have interests and are, therefore, sentient. More so, since animals have interests, they are entitled to moral consideration. Every genuine interest should be treated with the same weight, regardless of whether it is an animal or human being. He describes eating animals as an unnecessary imposition of pain and suffering upon animals. Human beings satisfy their dietary preferences by inflicting such pain on animals, but beyond that, no good comes of it. This gets based on the fact that even heavy consumption of meat poses serious health dangers to human beings. Singer views the use of animals in a scientific experiment as a morally defensible act in the fact that it produces knowledge and in particular medical research. Since medical research produces cures for diseases, there are more goods to be balanced against the pain and suffering of animals. This benefit is much better than the human satisfaction obtained from meat consumption. Singer’s view is based on moral reasoning based on a cost-benefit analysis. Singer’s view on euthanasia and abortion are consistent with his general ethical principles. Singer categorizes euthanasia into non-voluntary, voluntary and involuntary. Singer only consents to voluntary euthanasia in the fact that there are no other interests to be weighed against the interest of a person. In Singer’s view, abortion is wrong in that it is the killing of an innocent human life. This argument is deductively valid in that a fetus becomes a human being from the point of conception (Singer 98). Although Singer finds this argument flawed from the fact that child development is a gradual process, the validity still lies in the fact that life as a journey starts at the point where life begins; conception. Singer states that the arguments for or against abortion should be based on a utilitarian perspective. This perspective compares the interests of a woman against the interest of the fetus. He believes that any interest sought to be gained or avoided; despite all the harm or benefits caused corresponds directly to a person’s satisfaction or frustration. He argues that, at around eighteen weeks, a fetus has no ability to experience sensations like satisfaction or frustration which is a prerequisite to having any interests (Singer 63). Therefore, from a utilitarian perspective, nothing can be weighed against a woman’s interest to have an abortion. As a result, abortion is morally permissible. Immanuel Kant