The use of animals in science.

Throughout the history of science the use of animals to test or prove theories has evolved and changed with the past of time, nowadays we could consider a lot of those experiments as cruel or unethical in which it can be consider that some kind of harm is made to the animals in the experiments.
In the present paper, the author will compare the different perspectives of the ethic value regarding to the use of animals in the scientific área, specificly in the psychology subject.

In phycology, the use of animals in order to create theories, explain behaviors or prove them has brought what people could consider as negative effects on them. Meanwhile in the other perspective, it is consider that this effects on the animals are a risk that is worth taking having in mind the posible results.
Sometimes in psychology is more practical and easy to work in the experiments with animals instead of humans to describe, predict and make knowledge about the behavior. Scientists like Iván Petróvich Pávlov, John Broadus Watson and Barrhus Frederic Skinner important influents on the Conductism paradigm used animals in their experiments to create knowledge. But is it really ethic the way that scientist use animals to generate scientific progress?  

In a retropespective look, there is a differance in the creation of figures and ethic rules that aims to protect the animals in scientific experiments, but nonetheless there are positions wich considers that any use of  animals in this experiments is unethical and should not happen, this paper will point out the perspectives to make a reflection on this subject.