For many centuries people have experimented on animals. The two main reasons for doing this is first, to find out more about the animals themselves, and, secondly, to test out substances and procedures to see if they are harmful and decide whether it can be used on human beings or not. In the second category fall cosmetic products as well as medicines and surgical techniques.

There is a growing consensus that it is not acceptable to test cosmetic products on animals. This debate is about whether we should experiment on animals for scientific and medical purposes.The debate about the pros and cons of animal experimentation is one that elicits very strong emotions: animal rights activists have resorted to trespass, violence, and death threats. Con: Experiments on animals should be considered on a case-by-case basis. However, reduction of human suffering is our first priority and the prevention of animal suffering or death is. So that if there is a decent chance that an experiment will result in an important medical breakthrough that will reduce human suffering and death then it is justifiable to allow animal suffering.

Pro: Animals have the right to be treated as beings of value in themselves, not as the means to human ends. This principle must be applies in order to guarantee the end of cruelty to animals. The meaning of this principle means that animals should not be experimented upon whatever the potential gain for humanity. To infect monkeys with the AIDS virus or to expose rodents to toxic chemicals and radiation is simply not acceptable, whatever the supposed benefits. Con: Although in principle it is more important to reduce human suffering that to prevent animal suffering, in practice it is possible to keep animal suffering to an absolute minimum.

How ever, animal experimenters can test animal with medicine that are good for human and also can keep animals in clean, comfortable and healthy conditions. In short, it is possible to experiment on animals without being cruel to animals. Pros: In practice, as everyone knows, animals are not routinely treated well by animal experimenters. Apart from the fact that millions of animals die each year in experiments and others are often abused by handlers and experimenters.Con: Past experience has shown what invaluable advances can be made in medicine by experimenting on animals, and that live animals are the most reliable subjects for testing medicines and other products for toxicity. In many countries all prescription drugs must be tested on animals before they are allowed onto the market.

To ban animal experiments would be to paralyze modern medicine, to stop human suffering, and to endanger human health by allowing products such as insecticides onto the market before testing them with toxic.Pros: In fact few breakthroughs have been made as a result of animal experimentation - its advocates have overstated its achievements. There has been a catalogue of errors and failures in animal testing, which leads the animal to their death; as many as half the drugs that have been approved in the US and the UK after animal testing have subsequently had to be withdrawn because of harmful side-effects. Furthermore, there are alternatives to many tests that are currently done on animals - e. g. growing tissue or cell cultures from human cells in the laboratory.

Con: Human beings share about 99% of their genes and only slightly fewer with other monkeys. As a result, the reactions of these creatures are a very good guide to possible reactions of human patients. Even lower down the scale, some other animals share the same basic with humans. Furthermore, it would be immoral to risk the life of a human being when a medicine or procedure could instead be tested on a non-human animal. Pros: In fact, most animal experiments are done on animals that are nothing like human beings - rats and mice - which undermines the argument that these experiments are a reliable guide to human reactions.Scientifically, as well as morally, most animal experimentation is to be rejected - the reaction of a mouse to a substance is no guide to human reactions.

Each species has its own unique physiology. And the more similar an animal is to a human being - e. g. a chimpanzee - the more intelligent and sentient it is, and so the more immoral it is to treat is as a disposable and worthless biological object. Con: What is often overlooked in this debate is the subject of veterinary medicine.

It is in the interests of animals themselves that experiments be done on animals to test medicines and surgical procedures for using on animals themselves, not just on humans. Animal experimentation can be in the interests of animals as well as of humans. Pros: It is only acceptable to test human medicines on human beings if they give their consent. Non-human animals are never able to give such consent. It is therefore never acceptable to test medicines on perfectly healthy animals, even if the treatments are for use on other animals.