Tā bèi yùwéi èrshí shìjì zuì jù yǐngxiǎolì de sīxiǎngjiā.
She is regarded as the most influential thinker of the twentieth century.
Tips
memory
思想 (sīxiǎng) means 'thought/ideology', and 家 (jiā) is a suffix for experts or masters of a field — so 思想家 is literally 'a master of thought'. The same pattern applies to 科学家 (scientist), 政治家 (politician), 艺术家 (artist).