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James Rachels: The Moral Implications of Evolution

In Created From Animals, James Rachels cogently argues that scientific knowledge, in particular the evolution of species, dissolves many of the assumptions which form the foundation of traditional morality. The notion that, by virtue of being human, one is entitled to special moral treatment, is no longer tenable in light of our scientific understanding of the world around us.

Before scientific enlightenment, it was thought that Earth was the centerpiece of the Universe. Humans were supposedly created by God in his likeness. Animals, created by God as fundamentally lesser beings, were under human dominion. Given this view of the world, humans were set apart from animals and had a special God-given moral standing. In general, the moral framework of the time was consistent with our understanding (or lack of understanding) of the world.

Our knowledge of the evolution of species, and earlier of basic astronomy, has eliminated many of the assumptions from which traditional morality could follow. Science has revealed that Earth does not have a special place in the Universe, and humans and other animals are evolutionary products of the same nature. In The Origin of Species, Darwin himself stated that the boundaries we define between species are largely arbitrary and for convenience. Given this continuity of species, it cannot logically follow that only humans have categorical moral worth. Nevertheless, deeply-engrained moral views, even if no longer consistent with our own knowledge of the world, should not be expected to immediately collapse. In general, philosophers have been slow to assimilate scientific knowledge and to explore its consequences, and lay people often hold onto the comfortable moral views they have known since childhood, and which have been passed on from generation to generation. Only relatively recently have the human-to-nonhuman moral implications of Darwin's work been seriously considered.

Critics of extending morality to other sentient beings often state that the quality which really sets humans apart from other animals is the ability to reason. The notion that only humans can reason contradicts both Darwin's observations (The Descent of Man) and our current knowledge concerning many other species. It is true that only humans engage in philosophical discussions and mathematics, but this ability to reason is a difference in degree, not in kind. Furthermore, Rachels makes a strong case that the ability to reason is not usually relevant to moral consideration.

Given that humans and other animals are products of evolution, as opposed to immutable creations with unique essences, Rachels supports the idea that moral consideration should be a systematic, rather than a dogmatic, process. Insofar as animals are similar to humans, they should be treated similarly; insofar as they are different, they may be treated differently. For example, both rabbits and humans are sensitive to physical stress, and both species seek to avoid suffering. On the other hand, humans have far greater intellectual abilities. But both, only one, or neither of these qualities might be relevant to a given situation or treatment. Consider the common Draize test, in which the safety of new chemicals is evaluated by dripping them into the eyes of restrained rabbits. Such treatment of humans is not morally acceptable, nor should it be of rabbits since they too are very sensitive to such external physical stress. The lack of a rabbit's intellectual abilities are morally irrelevant to the situation since his physical suffering is not associated with intellect. On the other hand, a rabbit's lack of intellect precludes him from having an interest in--say--language. To deny him any exposure to language cannot be deemed immoral, though such treatment in the case of a human would be. The shared sensitivity of humans and rabbits to external physical stress is morally irrelevant to the exposure to language, just as intellect is irrelevant to physical [mis]treatment. In fact, we treat animals in many ways in which it would be deemed immoral to treat humans, but such treatment cannot be justified in the absence of a relevant difference. The principle of treating like cases alike is essential to a consistent moral code; without it, justice is simply not possible.

Rachels points out that humanity is still within the process of exploring the moral implications of being akin to the animals. If we are to act reasonably and ethically, it is inevitable that we adopt a moral code which is once again consistent with our understanding of the world and our place within it.

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