hito wo damasu niwa
aite no kimochi wo
shiru hitsuyou ga aru 人を騙すには相手の気持ちを知る必要がある
In order to deceive [someone], there's a necessity to understand [their] feelings.
To deceive someone, you need to understand how they think.
kotoba ni kufuu wo suru hitsuyou ga aru 言葉に工夫をする必要がある
There's a necessity to [think carefully about your] words.
You can't just speak carelessly, you need to be scheming.
