Shallow; superficial; thoughtless — describing actions or judgments made without careful or deep consideration.
そんな浅はかな考えでは失敗するだろう。
With such a shallow way of thinking you will probably fail.
彼の浅はかな行動が問題を大きくした。
His thoughtless actions made the problem worse.
浅はかだと周囲に笑われた。
He was laughed at by those around him for being foolish.