A process that directly activates any of the steps required for tolerance, a physiologic state in which the immune system does not react destructively against the components of an organism that harbors it or against antigens that are introduced to it. [ http://openisbn.com/search.php?q=0781735149&isbn=1/ GOC:jal http://purl.obolibrary.org/obo/go/references/0000022 ]