When tenth that something is scientist, usually we give to understand that he is authentic, evident and safe. For that reason, all want that their area of knowledge is treated like scientist. Other fields of study are described like pseudo-ciencientficos or false sciences, whose medical instructors denominate to their scientific activity and they even use the scientific language. But, how can be separated the scientist than he is not it? It is not easy task. To delimit the borders of science would be a work without xito1. This border that separates the science of pseudo-science is defined by the demarcation criterion that is used. This one has been object of debate of many scientists and philosophers of the science of century XX. Kant settled down that the judgments that constitute all science you must a priori be synthetic.
Synthetic because there are to be extensive, that is to say, our knowledge of science has to be extended. And a priori because its truth cannot depend on the experience, which is particular and nonuniversal; this way also they are necessary. This one is an example of demarcation criterion. As so saberes prevails to others to be called scientists. Another criterion of demarcation would be the one that established the Circle of Vienna: he is only scientist what he is empirically verifiable. What it is not possible to be demonstrated by the experience is not true nor false, makes no sense, is not scientist. Popper was critic before the Circle of Vienna.
Its criterion of demarcation was based on the falsabilidad. This one establishes that verifying continuously a theory does not serve to prove its validity because can have an object that has not been put under analysis and that denies that theory. Many verifications do not prove the absolute validity of a theory but a single refutes that it invalidates it.