The article presents an attempt to substantiate a new methodological paradigm of studying social interactions. The author proceeds from the postulate that man, being a live system existing by assimilation of energy resources dispersed in environment, is ontologically oriented at non-equivalent exchange with his milieu; it is argued in the article that any interaction between people is effectuated around and a propos of some sources of well-being, i.e. factors apt to ensure inflow of energy resources. In the author's interpretation, the extent to which inter-agent interactions prove reciprocally beneficial and, thus, durable, is conditioned by the notion justice which presupposes that (1) each participant of the exchange interaction should gain more than he, or she, gives up, and (2) the rate of profit should be the same for all. There is obviously a clearance between the two conditions of justice: for the contract of inter-agent interaction to be concluded, it is sufficient that such interaction be beneficial for all of its participants, but this is far from ensuring equal rate of profit; and it's exactly the said clearance that is regarded by the author as the clue to explaining all contradictions and collisions that occur in the sphere of social relations.