If we want to foresee the future of mathematics, the proper way to achieve it is to study the history and current state of this science. The presentation of technical texts can be problematic given the symbols used and their form of presentation. A clear example of this is the superscripts and subscripts that are used in areas such as mathematics, physics, and chemistry. The objective pursued is to present the central ideas, placing special emphasis on those development currents that have been shown to be the most important throughout the main periods of the history of mathematics, and which have exerted an outstanding influence in orienting and giving shape to the subsequent mathematical activity.

Great attention has also been paid to the very concept of mathematics, following the changes that this concept has experienced throughout the different periods, as well as the idea that mathematicians have had of their own actions. The book is organized by emphasizing the important mathematical issues rather than the men who developed them. It is true that every branch of mathematics bears the stamp of its founders, and that great men have played decisive roles in determining the course to be followed by mathematics, but it is their ideas that we want to present; the biographies will be considered as totally subordinated.

**We have followed, in this respect, Pascal’s advice:** Readers who have even a basic knowledge of the dozens of major fields cannot be expected to know the essence of all these developments. Therefore, and except in some very elementary subjects, the content of those whose history is being studied is also explained, thus unifying the exhibition in a certain way with history. These explanations of the various theories may not completely clarify them, but they should give at least an idea of their nature. Consequently, this book can serve in a certain sense as a historical introduction to mathematics; this approach is certainly one of the best procedures to get to understand and appreciate a theory correctly.

For mathematics students, this book may present another type of interest. The usual courses present mathematical theories that seem to have little relation to each other. History can give the global perspective of the subject and relate the subjects of the courses not only with each other but also with the central lines of mathematical thought. Also, these courses are also deceptive for another basic reason: they give a presentation of a logically organized theory, which leaves the impression that mathematicians have advanced from one theorem to the next in an almost natural way, which can overcome any difficulty, and that the theories are already completely trite and finished. The imposing succession of theorems plunges the student into misery, especially if he is beginning to study the subject.

History, on the contrary, teaches us that the development of any branch of mathematics has been carried out in a gradual way, based on results that used to come from different directions. It also teaches us that it has often taken decades, and even hundreds of years, of effort before making any important progress. And instead of the impression that the theories are already completely trite and finished, one finds that, often, what has been achieved is simply a point of departure, with which many gaps have yet to be filled, or with which there still remains to be made the really important generalizations.

#### What to measure in RH?

“What do I want to measure for? Understanding that each organization will have different answers, some will want to compare themselves with the industrial sector. Others will want to establish starting points to identify progress or generate feedback to the different units and areas of their organization. Some will want to establish parameters of the effectiveness of the HR team in the execution of their tasks and perhaps some will want to demonstrate that in the field of human capital there are also ‘hard’ indicators. All valid reasons for the implementation of metrics, our experience is that there is no single reason and there is not the best HR scorecard, everything will depend on the reality of the organization, its challenges and its level of maturity in HR processes “.

RH measures to have reliable data. The data is necessary to evaluate the employee’s performance, competencies and development needs. This allows a more strategic approach to developing workgroups and individuals. In addition, HR departments need multiple data sources, to correlate important information, which is not available with an evaluation from a single source. HR teams are called to be strategic in the organization and, more importantly, they must successfully link their strategy to that of their organization. In the past, it was almost impossible to achieve this, due to the lack of data. The desired is achieved in a “deterministic” manner, that is, free of risk. This depends on the influence that non-controllable factors may have on the determination of the results of a decision and also on the amount of information.

The issue of measurements in people management has been a recurring theme, as well as the validity of a concern common to all RH management. In several editions we have sought to unravel the strengths and weaknesses of a dimension that is executed, however, it is not always reflected on it. To measure in RH in the last term is to analyze the behaviors of people in an increasingly complex world. Beyond numbers and efficiency:

What doubt is there, measuring is not a neutral act! Behind the tools and methodologies that are used (the technical factor) in research and assignments, there is a vision or paradigm regarding the reality that wants to be measured. If we use only quantitative tools, for example, beyond being more ‘digestible’ to manage, we are addressing reality from logic of efficiency in which numbers are more accurate when quantifying results. But numbers have their efficiency and also their limitation.