In those States organized territorially in a decentralized form, the principle of solidarity presents two dimensions, one of personal or individual character (solidarity between citizens), and another one of territorial or communitarian character (solidarity between States, Regions, Autonomous Regions). In the Spanish Constitution of 1978, the absence of constitutional references to the first dimension of solidarity contrasts with the express reception of this second dimension, interterritorial solidarity, in articles 2 and 138. In that context, the object of this study is to determine the meaning and reaches of the principle of solidarity in the Constitution of 1978. The scheme used is the following one.
First of all, it is shown how, in spite of its express recognition, the constitutional regulation of interterritorial solidarity is clearly insufficient. Next, and that is the central nucleus of the work are analyzed the different dimensions (political, legal and economic) of the principle of solidarity. Finally, some conclusions on the existing relation between the principles of solidarity and autonomy are extracted, relation that not always has been well understood.