(n.) The act of preconceiving; conception or opinion previously formed.

assumption bent bias delusion favoritism forejudgment idee fixe illusion inclination jaundice jaundiced eye leaning one-sidedness parti pris partialism partiality partisanship preapprehension preconclusion preconsideration predecision predetermination predilection predisposition prejudgment prejudication prejudice premature judgment prenotion prepossession presumption presupposal presupposition presurmise twist undetachment undispassionateness