白 bái: white
云 yún: cloud
苍 cāng: gray
狗 gǒu: dog
Surprise — it’s not a war story! This idiom comes from a poem by Tang dynasty poet Du Fu.
There was once an aspiring poet named Wang Liyou whose wife left him because he was poor. The town gossip mill started churning and people began to suspect that Wang Liyou had been the one to leave his wife because he was having an affair.
Du Fu, however, could see the truth of the situation and subsequently wrote a poem about Wang Liyou’s troubles. The poem is called 可吹 kě chuī and it contains an iconic line about the ever-changing nature of human perception. Du Fu points out that clouds in the sky can take on many forms, and often just as quickly as we recognize a familiar shape in them, they change form once again. Thus, a fluffy white cloud can just as easily be perceived as a gray dog.