Any human activity, such as playing cards, read a newspaper, driving a car, requires some specific knowledge; every activity requires, then, its own special forms of knowledge, that is why knowledge is another value indispensable and ubiquitous in our lives, whose benefits are priceless. This simple view may seem too trivial and obvious, but often happens that we do not give due weight to it and not take it into account in everyday life. Knowledge has the fundamental function of presenting a model of the world where we live and to make available all other values that guide us every day; a lacking or distorted knowledge can provoke enormous damage, so it is appropriate to stop and reflect on those concepts.