The phrase "assume as true" often implies a tentative or speculative belief in a statement or assertion. When searching for synonyms with similar connotations, one may consider phrases such as "presume," "suppose," "posit," or "assert." Each of these words communicates a degree of confidence in the statement, but still maintains a level of uncertainty. Other potential synonyms might include "conjecture," "postulate," "hypothesize," or "speculate," which tend to suggest a greater degree of doubt or speculative inquiry. Ultimately, the choice of synonym will depend on the specific context and intent of the statement, as well as the level of confidence and certainty with which the speaker wishes to convey their belief.