Publishing A Theory of Justice in 1971 John Rawls defined a conceptual realm of justice as that of a well-ordered society in which some principles of justice should be tested before seeking to apply them to distribute primary goods among co-operative representative subjects (considered as equals within the basic structure of society) and other subjects, who are not necessarily co-operative, even if they are included in the contract of justice by the representatives through the indirect moral duties theory. Representative subjects were interested in possessing and preserving - for themselves and for their descendants - all kinds of goods: natural, primary, social and public ones. They are interested in maintaining economic and social distinctions obtained by fair work distribution, as well. In explaining his theory of a fair distribution of primary social goods, John Rawls does not include, at least explicitly, the kind of goods I am suggesting in this paper to be called natural environmental goods, the kind of goods which are indispensable to secure, with no exception, the survival of all organisms subjected to basic needs, including human needs. Natural environmental goods seems to have been forgotten by Rawls, or at least considered as not implicated in his model of a fair institutional distribution of primary social goods. Following what Michael S. PRITCHARD, Wade L. ROBISON, Russ MANNING, Brent A. SINGER, Daniel P. THERO and Troy W. HARTLEY have critically pointed in some of their articles, I am going firstly to show the lack of the concept of natural environmental goods in Rawls’ Theory of Justice, and secondly, I suggest considering natural environmental goods as part of a non-speciesist theory of justice. So, I hope to contribute to extend the philosophical legacy of A Theory of Justice, in order to include in our moral consideration needs and interests of all living beings. In other words, I will try to consider the issue of justice not just as a question of rationality but of reasonability.