However, in the psychological science there is no sufficient facts to establish a unique and robust system. (Psychologies of the twentieth century, p. 17). In this way, the positivist scientific psychology, which is instituted in terms of true knowledge as has been raised in the debate, has rejected any concept which does not come from experience, being the fact the only scientific reality. Through observation and experimentation, it attempts to explain reality by formulating laws, establishing connections that are generalizable between variables, using the hypothetical-deductive method. One of the features, in my opinion very open to criticism of the positivist scientific psychology, is the fact of denying the investigated objects of social content, following the guide of scientific rationality, for which there is no particularity and concrete, on a search for general explanations. Not you deal with emotions, motivations, or consciousness, with an eminently subjective weight and not observable, being eliminated as an object of study.
All these deletions can be interpreted as a means to establish a method more scientific as possible, or as close to what is called as a scientist in their fight by erecting as experimental science. As an example of the positivist scientific psychology, mentioned a objective psychology of the Russian Pavlov and Bekhterev, Throndike reflexology with the law of effect and his theory of stimulus-response to Behaviorism. A behaviorist dira: something of what you can’t give account on empirically observable terms (scientifically) no way part of my inquiry as a scientist. By way of example, Watson asserted the need to rid completely of concepts such as consciousness and mind for lack of sense in terms of the requirements of scientific method and replace them with others that Yes met them as it is of the conduct; He said: If you want to become science psychology should follow the example of the physical sciences, that is, become materialistic, mechanistic, deterministic and objective.