Two or more system members combining together to form one member, whether temporarily or permanently (“integration” and “fusion” generally refer to permanent mergings). Merging is also used to indicate a more complete form of blending. Many therapists think that merging all members of a system together will make for a happy and functional singlet. While this does work for some systems or partial integration may be necessary for some systems, it does not work and/or is not desirable for other systems. For the latter, this can be because it doesn't last indefinitely, may hurt healthy functioning, lead to feelings of loss, etc. or just otherwise not be desired (many systems see integrating with their systemmates as akin to killing them).