"Knew no alternative" refers to being limited or confined to a certain option or course of action. Synonyms for this phrase include being stuck, with no other option, having no choice but to, forced to, bound by, or constrained by circumstances. These synonyms all imply a lack of freedom or autonomy in decision making. It suggests being in a position where one has to follow a certain path, regardless of personal preferences or beliefs. In such situations, it is essential to explore creative alternatives and find potential solutions to challenge the status quo and find new possibilities by breaking free from limiting beliefs and embracing new possibilities.