14世紀中期，“相反的，對立的，在相反的點或方向上； 極不相似，最不相似”，源自盎格魯-法語 contrarie，古法語 contrarie，直接源自拉丁語 contrarius “相反的，對立的； 相反的，反向的”，源自 contra “反對”（見 contra）。意思是“愛反駁的，倔強的，難以駕馭的”來自14世紀晚期； “不利的，不利的”意思來自14世紀晚期。相關： Contrarily。
作爲名詞，來自13世紀晚期，“一對字符、命題、術語等中最不同的一個”。短語 on the contrary “與所說的完全相反”自約1400年以來被證明爲 in the contrary。
If we take the statement All men are mortal, its contrary is Not all men are mortal, its converse is All mortal beings are men, & its opposite is No men are mortal. The contrary, however, does not exclude the opposite, but includes it as its most extreme form. Thus This is white has only one opposite, This is black, but many contraries, as This is not white, This is coloured, This is dirty, This is black; & whether the last form is called the contrary, or more emphatically the opposite, is usually indifferent. But to apply the opposite to a mere contrary (e.g. to I did not hit him in relation to I hit him, which has no opposite), or to the converse (e.g. to He hit me in relation to I hit him, to which it is neither contrary nor opposite), is a looseness that may easily result in misunderstanding; the temptation to go wrong is intelligible when it is remembered that with certain types of sentence (A exceeds B) the converse & the opposite are identical (B exceeds A). [Fowler]
如果我們接受 All men are mortal 這個陳述，它的相反是 Not all men are mortal，它的轉化是 All mortal beings are men，而它的相反是 No men are mortal。然而，相反並不排除相反，而是將其包括在其最極端的形式中。因此， This is white 只有一個相反的， This is black，但有許多相反的，如 This is not white, This is coloured, This is dirty, This is black； 而最後一種形式是被稱爲 contrary，或更強調的 opposite 通常是無關緊要的。但是，將 the opposite 應用於僅僅相反的（例如，與 I hit him 無關的 I did not hit him 相對），或者與轉化（例如，與它既不相反也不相反的 He hit me 相對）是一種鬆散的做法，這可能很容易導致誤解； 當記住對於某些類型的句子（A exceeds B）轉化和相反是相同的（B exceeds A）時，犯錯的誘惑是可以理解的。[福勒]
