53
" That those who aim at happiness for happiness's sake often fail to find it, whereas others find happiness in pursuing altogether different goals, has been called ‘the paradox of hedonism’. It is not, of course, a logical paradox but a claim about the way in which we come to be happy. Like other generalizations on this subject, it lacks empirical confirmation. Yet it matches our everyday observations and is consistent with our nature as evolved, purposive beings. Human beings survive and reproduce themselves through purposive action. We obtain happiness and fulfillment by working towards and achieving our goals. In evolutionary terms, we could say that happiness functions as an internal reward for our achievements. Subjectively, we regard achieving the goal (or progressing towards it) as a reason for happiness. Our own happiness, therefore, is a by-product of aiming at something else and is not to be obtained by setting our sights on happiness alone. "
― Peter Singer , Practical Ethics
57
" People sometimes think that all animal experiments serve vital medical purposes and can be justified on the grounds that they relieve more suffering than they cause. This comfortable belief is mistaken. The LD50 – a test designed in the 1920s to find the ‘Lethal Dose’, or level of consumption that will make 50 percent of a sample of animals die – is still used today for some purposes. It is, for example, used to test the popular anti-wrinkle treatment, Botox® Cosmetic. For this purpose, mice are given varying doses. Those given a high enough dose slowly suffocate as their respiratory muscles become paralyzed, undoubtedly after considerable suffering. These tests are not necessary to prevent human suffering: even if there were no alternative to the use of animals to test the safety of the products, it would be better to do without them, and learn to live with wrinkles, as most elderly people always have. "
― Peter Singer , Practical Ethics
58
" The instrumental defence of speciesism invokes the widely used ‘slippery slope’ argument. The claim is that a first step in a certain direction will put us on a slippery slope, and we shall not be able to stop sliding into a moral abyss. In the present context, the argument is used to suggest that we need a clear line to divide those beings we can experiment on, or fatten for dinner, from those we cannot. The species boundary makes a nice sharp dividing line, whereas levels of self-awareness, autonomy or sentience do not. Once we allow that any human being, no matter how profoundly intellectually disabled, has no higher moral status than an animal, the argument goes, we have begun to slide down a slope, the next level of which is denying rights to social misfits, and the bottom of which is classifying anyone we do not like as sub-human and eliminating them. "
― Peter Singer , Practical Ethics