Solidarity", a much-used word, is a recent word in the history of Western ideas and represents a complex knot of relationships that attempt to respond to a certain human condition. Everyone tries to find in it appeals to a human "essence" that goes beyond the subject and that opens up to others, whether circumstantially or permanently; emblematic projects, small and majestic works of charity, collaboration in the face of some human difficulty, empathy in the face of pain and frustration, displays of affection and many other actions and attitudes are labelled with the genitive of "solidarity". There are some who place it as a synonym for volunteering and cooperativism, and there are even others who deny it as an element that disturbs the demands of social justice that should exist between human beings or between institutions and individuals. But above all, solidarity is presented as a new way of referring to the human condition, in order to highlight its inescapable social character.