A treatise is a long, serious piece of writing that works through one subject carefully and completely — a book or a long article, written by someone who wants to lay out everything they know and argue it properly. It is not a report, not an essay you write for homework, not a news article. The feeling of the word is: thick, formal, old, academic. Famous ones have this word in their titles — Hume's 'A Treatise of Human Nature'.

A treatise is a long, serious piece of writingTreatise是一篇又長又嚴肅的文章 that works through one subject carefully and completely仔細、完整地把一個主題講透——a book or a long article可能是一本書，或一篇長文章，written by someone who wants to lay out everything they know and argue it properly由想把自己知道的一切都攤開來、好好論證的人寫的。It is not a report, not an essay you write for homework, not a news article它不是報告，不是你寫作業的那種essay，也不是新聞文章。The feeling of the word is: thick, formal, old, academic這個詞給人的感覺是厚重、正式、古老、學術。Famous ones have this word in their titles有名的作品會把這個詞放進書名裡——Hume's 'A Treatise of Human Nature'像休謨的《A Treatise of Human Nature（人性論）》。

Two things to notice about how people actually use it. First, it belongs to the library, not to conversation; you will meet it far more in reading than in speech.

Two things to notice about how people actually use it關於這個詞實際的用法，有兩件事值得注意。First第一，it belongs to the library, not to conversation它屬於圖書館，而不是日常對話；you will meet it far more in reading than in speech你在閱讀裡遇到它的機會，遠比在說話裡多。

Second — and this is the fun part — modern speakers most often use it as a small joke. If a friend sends you a very long message explaining why one restaurant is better than another, you can say "thanks for the treatise". That teasing use is now so common that some people meet the joke before they meet the real word. The joke only works because the real word is so heavy.

Second — and this is the fun part第二——有趣的地方來了——modern speakers most often use it as a small joke現代人最常把它拿來開個小玩笑。If a friend sends you a very long message explaining why one restaurant is better than another如果朋友傳了一大串訊息，解釋為什麼某間餐廳比另一間好，you can say "thanks for the treatise"你可以說「謝謝你這篇treatise」。That teasing use is now so common這種調侃的用法現在太常見了 that some people meet the joke before they meet the real word有些人是先認識這個玩笑，才認識這個詞真正的意思。The joke only works because the real word is so heavy這個玩笑之所以成立，正是因為這個詞原本很沉重。

Note also that it is pronounced with the 's' as a soft sound at the end and is completely unrelated to a peace agreement, which is 'treaty' — different word, different job.

Note also that it is pronounced with the 's' as a soft sound at the end另外要注意，它結尾的's'唸成輕柔的音，and is completely unrelated to a peace agreement而且跟和平協議完全沒關係，which is 'treaty'那個字是「treaty」——different word, different job不同的詞，不同的功用。