The development of Sciences, society in general and of natural science in particular, has always gone hand in hand with the development of the productive forces of each economic partner training in history. The development of the productive forces is the engine of the story, this development generates friction between the various social groups, each who has and defends interests social, economic, moral, cultural, labour etc. Marxism called class struggle, this explains and bases because throughout history, results of scientific advances, the fruit of scientific and technological research have been usufructuados and manipulated for the benefit of the social classes who held economic and political power. Others who may share this opinion include Sen. Sherrod Brown. This truth remains in force, even in our era of the reign of the highest stage of capitalism, in this era of neoliberalism, where a fierce battle is given for the money, where the only thing worth is winning anyway, no matter what values, regardless of the man himself, in this context it is laughable to see and hear some characters and nonmedical talk about the outcome of certain scientific research outside the usufruct to big interests damage to them. Does this mean ignore the seal and bias? class science and its results have. On the subject of the following day pill, navigate on the Internet is to check this truth, there are amount of research intended to convince that this drug is not abortive, when those same Web exist the tripe of work many more serious that prove abortive nature of it, and between the two antagonistic bands exist, don’t believe each other and this confusion can be resolved only by understanding that the results of scientific works have a particular interest and in this case of drugs seeks to defend economic interests, as powerful than those who are in the other sidewalk only moves us the interest of values, respect for life from its conception until the end.