Learning Acceptance: Metta and REBT

 Metta, or loving kindness, is an interesting practice in Buddhism which I have studied before as part of my master's degree. I have often wondered, is it ever possible to wish loving kindness to all beings? What happens when it feels insincere, as when there are judgments or thoughts that override that loving kindness?
  I am thinking that in fact the practice of loving kindness would go very well alongside something like Albert Ellis's Rational Emotive Behavioral Therapy (REBT), in the sense that both practices are really based on finding an acceptance within that is unconditional, and then extending that USA (Unconditional Self Acceptance) to UOA (Unconditional Other Acceptance). I think that whereas the latter is devoted to the idea of challenging the notion that acceptance is conditional or necessitated by something external to oneself, loving kindness practice is more devoted to embodying the basis for unconditional acceptance, which is a kind of non-dualistic attitude. Non-dualism seems quite crucial because unless a person can get to a state where they are not fixated on thinking of themselves in terms of shoulds and shouldn'ts, they may have an intellectual understanding of acceptance but not a realization that feels authentic and embodied. Perhaps the two ideas of metta and RBT could be taught together as part of a comprehensive form of therapy.
   At the same time, I think that metta practice by itself would not necessarily be sufficient for everyone, because there are often times when a reflective process is needed to know why we lack compassion or acceptance toward self and others. This is where I believe that REBT can play a big role in helping people to identify what stops them from feeling acceptance, and even to adjust their thinking so that they are not so swayed by negative thoughts about themselves. Could these practices somehow be combined into one therapy, a kind of LK-REBT? The acronyms are multiplying now! But nonetheless, the idea has a kind of potential that I would like to explore, especially where it relates to a key intersection between Western therapy and Eastern philosophies.