CEDICT
to feel no qualms upon self-examination; to have a clear conscience
Wiktionary
凭着良心自我反省,无丝毫惭愧不安。
重編國語辭典
凭着良心自省,而没有丝毫惭愧与不安
維基詞典
"Having a clear conscience" is an idiom.
Source: Tatoeba