Animal experiments are widely used to develop new medicines and to test the safety of other products. Many of these experiments cause pain to the animals involved or reduce their quality of life in other ways. If it is morally wrong to cause animals to suffer, then experimenting on animals produces serious moral problems. Animal experimenters are very aware of this ethical problem and acknowledge that experiments should be made as humane as possible. It is also known that it is wrong to use animals if alternative testing methods would produce equally valid results.
Experimenting on animals is always unacceptable because it causes suffering to animals, and the benefits to human beings are not proven. The case against animal testing is that the level of suffering and the number of animals involved are both so high that the benefits to humanity do not provide moral justification. The equivalent case for animal experiments is that they will produce such great benefits for humanity that it is morally acceptable to harm a few animals.
Animal experiments are not used to show that drugs are safe and effective in human beings, as they cannot do that. Instead, they are used to help decide whether a particular drug should be tested on people. Animal experiments eliminate some potential drugs as either ineffective or too dangerous to use on human beings. If a drug passes the animal test it is then tested on a small group of humans before larger trials are done.
Animal experiments only benefit human beings if their results are valid and can be applied to human beings. Another problem with animal testing is that results can be misleading. Drugs that have negative effects on animals could potentially be highly beneficial to humans and vice versa. Those in favor of animal experiments say that the benefits to human beings outweigh the harm done to the animals being tested. This is a consequentialist argument, because it looks at the consequences of the actions under consideration.
It cannot be used to defend all forms of experimentation since there are some forms of suffering that are probably impossible to justify even if the benefits are exceptionally valuable to humanity. The consequentialist justification of animal experiments is done by comparing the harm the experiment will do to animals to the harm done to humans by not doing the experiment. This is not a valid way to justify the argument because this is ultimately comparing two different things.
The harm that will be done to he animals is certain to happen if the experiment is carried out. The harm done to human beings by not doing the experiment is unknown because no one knows how likely the experiment is to succeed or what benefits it might produce. It is morally worse to do harm by doing something than to do harm by not doing something. Looking at it that way, it is morally worse for experimenters to harm the animals by experimenting on them than it is to harm some human beings by not doing an experiment that might find a cure for their disease.
The benefits to humans does not outweigh the pain and suffering that all of the animals endure while going through experiments. The issue of animal experiments is very clear if we accept that animals have rights. If an experiment violates the rights of an animal, then it is morally wrong because it is wrong to violate rights. The possible benefits to humanity by performing these experiments are completely irrelevant to the morality of the case, because rights should never be violated.