Or perhaps "hypothesis", an unproved theory, tentatively accepted to explain certain facts or to provide a basis for further investigation.
Green-dot
fine by me, is this a substitue for postulation or an "as-in"
Incidently I'm fine with folks who openly hypothesize and/or postulate and/or even theorize later after many facts are known but not with speculation as it wastes time and gives the appearance to the casual reader that one can conclude