From the biography of Joaquin Costa, small upper- Aragon farmer, and his prodigious intellectual and working capacity, his main agrarian activities can be described. We continue explaining and offering bibliographical solutions: his work is so extensive and abundant and its edition had so many problems, that news about the possibility of approaching it with methodological guides and critics, and in many cases through the simple facility of the Internet is excellent. In the light of his main works, they are then analysed in terms of law and custom, old and new systems of collectivism and property, social problems of the rural society, common proposals of hydraulic policy, political connections of that agrarian perception, and the present validity of some of his main proposals
