倒果为因

The phrase appears in Lu Xun's 鲁迅 (Lǔ Xùn) essay 《科学史教篇》 (Kēxuéshǐ Jiàopiān, 'Lessons from the History of Science', collected in 《坟》 Fén), criticizing those who praise scientific results while ignoring the rigorous process that produced them — 倒果为因，莫此为甚 ('a more extreme reversal of cause and effect there could not be').

memory

Read literally: 倒 (reverse) + 果 (fruit/effect) + 为 (as) + 因 (cause) — 'turn the effect into the cause'.