Hans VaihingerThinkers

A Fiction (n.) is, ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠in Vaihinger's sense, a hypothesis we know to be groundless or absurd yet must act upon for practical reasons — religion above all.