理所当然[ lǐ suǒ dāng rán ]

⒈ 按道理应该如此。例就把来结识了这位大哥，也是理所当然。——明·冯梦龙《醒世恒言》英justifiably; a matter of course; as it ought to be; be both natural and right; it goes without saying; it is what propriety requires;

⒈ 以理而言应当如此。

引《醒世恒言·陆五汉硬留合色鞋》：“（这兜肚）就把来结识了这位大哥，也是理所当然。”《说岳全传》第五二回：“此乃各为其主，理所当然，何罪之有！”老舍 《柳家大院》：“谁还管青红皂白，先揍完再说，反正打媳妇是理所当然的事。”