This paper starts stating that in the realm of different disciplines that investigate processes and elements individually considered, it is not possible to elaborate an explanation of complex problems, in particular, of vital phenomena and human beings. The General theory of Systems provided a body of principles common to all systems and was projected as a media to unify the different disciplines. !is intention is shared with the Sciences of Complexity orientated towards the dynamic adaptive systems that are more complex. After observing the abscence an unified concept of complexity, the directions that investigation has taken and diversity of approaches, it concludes that, as happened with the General theory of Systems, it is probable that Science of Complexity does not succeed either in the intention of exceeding the reductionism and improve the exchange of knowledge between diverse specialized disciplines. Finally, it highlights that a problem is complex as long as it transcends the limits of a discipline and requires the engagement of specialists capable of creating a common frame of reference that includes the different elements of the system and its interaction.