在古典修辞学中，kairos指的是适当的时间和/或地点，即说或做正确或适当事情的正确或适当的时间。

“Kairos是一个具有多层含义的词，”Eric Charles White说，他是《Kairos：网络环境下写作教师杂志》的作者。White解释道：

"Most usually, it is defined in terms of its classical Greek courtroom nuances: winning an argument requires a deft combination of creating and recognizing the right time and right place for making the argument in the first place. However, the word has roots in both weavings (suggesting the creation of an opening) and archery (denoting the seizing of, and striking forcefully through an opening)."

在希腊神话中，宙斯最小的孩子凯罗斯是机会之神。根据提奥奇尼斯的说法，哲学家普罗泰戈拉是第一个阐述“正确时刻”在古典修辞学中的重要性的人。

朱利叶斯·凯撒的凯罗斯

在莎士比亚戏剧《凯撒大帝》的第三幕中，角色马克·安东尼第一次出现在观众面前（背着凯撒大帝的尸体）并犹豫是否大声宣读凯撒的遗嘱时，就雇佣了凯罗斯。在带来凯撒尸体的过程中，安东尼将注意力从角色布鲁特斯（他正在大声疾呼已经实现的“正义”）转移到他自己和被暗杀的皇帝身上；因此，安东尼赢得了一个非常专注的观众。

类似地，他故意犹豫是否大声宣读遗嘱，这使得他可以在没有透露遗嘱内容的情况下透露遗嘱内容，而他戏剧性的停顿也提高了群众的兴趣。这是kairos的一个经典例子。

凯罗斯在一封学生写给父母的信中写道

Kairos也可以用在信件中，比如这封学生写给父母的信。她用凯洛斯把父母从坏消息中拉出来，带到更坏的消息中去，尽管这是虚构的。

Dear Mother and Dad: It has now been three months since I left for college. I have been remiss in writing this, and I am very sorry for my thoughtlessness in not having written before. I will bring you up to date now, but before you read on, please sit down. I am getting along pretty well now. The skull fracture and the concussion I received when I jumped out of the window of my dormitory when it caught fire shortly after my arrival are pretty well healed now. I only get those sick headaches once a day. Yes, Mother and Dad, I am pregnant. I know how much you are looking forward to being grandparents, and I know you will welcome the baby and give it the love, devotion and tender care you gave me when I was a child. Now that I have brought you up to date, I want to tell you that there was no dormitory fire, I did not have a concussion or a skull fracture. I was not in the hospital, I am not pregnant, I am not engaged. I do not have syphilis and there is no man in my life. However, I am getting a D in history and an F in science, and I wanted you to see those marks in the proper perspective. Your Loving Daughter

选择正确的时间

Kairos真正的意思是在正确和适当的时间提供信息。

"Clearly, the notion of kairos points out that speech exists in time; but more important, it constitutes a prompting toward speaking and a criterion of the value of speech," says John Poulakos in a 1983 article titled, "Toward a Sophistic Definition of Rhetoric," published in the journal Philosophy and Rhetoric. "In short, kairos dictates that what is said must be said at the right time."

例如，请注意，上一节中的学生在选择正确的时间（她希望）告知父母她成绩不佳之前，是如何抛起一堵困惑的墙的。如果她马上告诉父母她成绩不好，他们可能会给予某种形式的惩罚，或者至少批评她的学习。通过拖延时间，让她的父母把注意力集中在所谓的可怕的消息上，这个学生能够选择正确的时间来传递真正的坏消息，从而像安东尼一样，让她的观众转向她的观点。那么，这就是凯罗斯的完美例子。