1) Promotion of peace 
• (n.) That branch of Christian science which treats of the methods of securing unity among Christians or harmony and union among the churches; -- called also Irenical theology.
I·ren'ics noun (Eccl.) That branch of Christian science which treats of the methods of securing unity among Christians or harmony and union among the churches; -- called also Irenical theology . Schaff- Herzog. 
the branch of theology dealing with the promotion of peace and conciliation among Christian churches. Cf. polemics (def. 2).