Purpose. The paper attempts to investigate the constructivist approach to the social world and its implications for social forecasting. Theoretical basis. Social forecasting is mainly based on the idea that a human is "determined ontologically". Using the methodology of the natural sciences, most predictions and forecasts fail to encompass all the multiplicity and variability of the future. The postmodern interpretation of reality gave impetus to the development of the new approaches to it. A constructivist approach to social reality began to compete with essentialism. Social constructivism asserts that reality is a set of mental constructs, that it is ultimately a text. Radical constructivism interprets reality as a specific system of meanings emphasizing the artifact aspects of our reality. An interpretation of the social actors’ behavior is based on the ways of understanding accepted in a given society/community and do not possess ontological universality. The creators of social space are also its creations. Originality. Within the framework of the postmodern approach to reality, the second-order forecasting, or forecasting of forecasting, is particularly relevant. That means that the observers-forecasters must be included in the forecast as a part of one-unified process. At this stage, a forecaster must realize that he/she is a part of a larger system, a part of the world he/she observes (and actually creates). The situation changes dramatically – the forecaster is forced to take responsibility for his/her own observations. This ultimately leads to the "humanization" of forecasting. Acting in our world full of uncertainty, unpredictability, and turbulence, modern researchers of the future should be mindful of powerful social constructs of reality. Conclusions. Social forecasting should be embedded in a wider context, which requires a joint effort of philosophers, foresight practitioners, historians, psychologists, sociologists, political scientists, religious scholars, anthropologists, etc. To develop promising visions and scenarios of the future, it is necessary to answer the question "Why?", which is the task of philosophically oriented research, because without this answer, we will deal with the consequences; and the implementation of the negative scenarios will reproduce itself in new socio-cultural and historical conditions. An in-depth understanding of this "Why?" provides opportunities to be in the flow of transformations. The study of the deep mental processes of the actors of social changes, the multidimensional influence on the transformation of social structures can gradually expand an answer to the question "Why?", that can cause positive changes and, accordingly, allow to create fruitful projects of the future and form effective behavioral strategies that correspond to the desired level of social development.