All motivation and action is based on an assessment of “reality”.
Public assessments include the sciences, mainstream psychologies and religions, various traditions such as the arts, sports, work, etc. The general elements of these assessment are agreed on by many people. This makes them sort of satisfying within a limited sphere of thought. They can hold a good deal of psychological water, but not all of it.
Private assessments are usually neurotic (mistaken) because even if shared with others, they tend to contain many unfounded assumptions. These assumptions often appear true to the individual but don’t hold up well if exposed to other views or better evidence.
Not only do neither public nor private assessments of reality as described above completely satisfy, but even when combined, they fail to fully satisfy. This is because the problem of interpersonal ambiguity cannot be answered in those ways.
FIML practice provides a means for partners to reach a reasonable assessment of reality that includes both wholesome public and wholesome private components. The private components are made wholesome through FIML practice because partners actually have the means to achieve satisfying mutual understanding, to remove ambiguity.
FIML partners should feel that they can say what they want to each other. They should also feel that they can refrain from saying things they don’t want to say.
Most people tend to see other people as being on some sort of scale–they might be seen as “normal” or “crazy”, “responsible” or “irresponsible”, “reliable” or “unreliable”, etc.
These scales are always a mixture of public and private components as described above.
FIML partners, in contrast, need only ask how is the non-FIML person adapting to ambiguity? What standards have they chosen or forced on themselves? What standards do they use to assess “reality”?
Their standards will always be skewed one way or the other. To simplify, they will either be fairly strict adherents to a public code or fairly eccentric adherents to private neuroses, or most commonly, a mixture of these two.
Even Buddhist practice can fall victim to this problem. Insofar as Buddhist practice is nothing more than an imported public standard, it cannot satisfy for long. Buddhist practice plus FIML will satisfy because FIML allows partners to establish mutual interpersonal standards that both of them can understand and agree upon completely. These standards are not the imported standards of someone else, but self-generated, mutually generated standards created by the partners themselves.
If you don’t fill the void of interpersonal ambiguity, you will have to compensate by compartmentalizing your life, importing standards from the public sphere, or generating your own neuroses (mistaken interpretations). This point may seem obvious or trivial, but it is huge. Emotional suffering, delusion, the First Noble Truth all stem from this problem.