vice versa; the reverse is also true
Used to state that the opposite of a previously mentioned statement is equally true. Often appears in formal or logical contexts. The variant 逆もまた然り is also common.
See also: 逆もまた然り
努力が成功を生む。逆も然りで、怠惰は失敗を招く。
Effort brings success. Vice versa, laziness leads to failure.
彼は私を信頼している。逆も然りだ。
He trusts me. The reverse is also true.
Standard kanji spelling; 然り is the classical copula meaning 'so' or 'thus'.
Kana spelling of 然り; common in less formal writing or when avoiding the kanji.
From 逆 (reverse) + も (also) + 然り (classical copula meaning 'so' or 'thus'). The phrase literally means 'the reverse is also so'.