A commonly shared goal among scientists is to reach the ‘holy grail’ of theoretical integration or unification. We list several examples of such attempts within sociology and psychology in general and, more specifically, within the subarea of social justice. A distinction is made between the seemingly interchangeable terms integration and unification. We note the scarcity of work concerned with untangling the meaning of theoretical integration, with differentiating among forms of integration, and with mapping the variety of ways in which integration might be accomplished. The five articles published in this issue of Social Justice Research, and here briefly reviewed, address these and related questions and/or exemplify theoretical integration with a focus on justice.