…They don’t want to mend their own ways, but each other’s*
(Rikkoku wo horobosu mono wa rikkoku nari;
“The one who destroys the six countries, is the six countries”)
When a nation falls, it usually isn’t ultimately due to external pressure; rather, internal strife, corruption, and other ills are usually to blame. By extension, in case of a failure, the first place one should look is within oneself instead of jumping to blame outside forces beyond one’s control.
Let’s start in the grammatical center and work outward, this time. About two-thirds of the way through this phrase we find the particle は (wa), telling us that what comes before it is the topic of conversation and what comes after is the comment on that topic. The noun immediately marked by the particle in this case is 者 (mono), “person,” although as we’ll see this “person” is more of a metaphorical active agent of change than a human individual.
What kind of mono is it? It’s one who does the preceding verb, 滅ぼす (horobosu), “to destroy,” “to overthrow.” The object-marker particle を (wo) in turn tells us that the thing(s) being destroyed is (are) a group of number-noun 六国 (rikkoku), “six countries.”
Meanwhile, the comment comprises the same number-noun 六国, followed by the copula なり (nari) in sentence-final form.
First, be careful: the 六国 in this rare saying is properly pronounced rikkoku, and NOT rokkoku, even though typing the former into your computer will likely produce 立国 and the latter is the reading you’d probably expect.
History! The “six countries” in question are 斉 (Sei in Japanese but Qi in transliterated Chinese), 楚 (So, Chu – which we’ve seen before), 燕 (En, Yan), 韓 (Kan, Han), 魏 (Gi, Wei), and 趙 (Chou, Zhao). These plus Qin (秦, Shin in Japanese) are the “Seven Warring States” of Chinese antiquity. Each country fell in turn to Qin, and it seems from this saying that historians blamed each nation’s internal problems rather than shrugging and leaving it at the thought that Qin must have had some overwhelming advantage.
*The title and intro line of this post are taken from the Piet Hein grook “Mankind.”
「慎君はね、モンハンでよく失敗するんだ。でも、いつも、バグのせいにして文句言うからちょっとうんざりなんだよね」 「六国を滅ぼす者は六国だって気づいてないようだね」 「え… シヴィライゼーションじゃないよ、モンスターハンターだよ」
(“Shin-kun wa ne, MonHan de yoku shippai suru nda. Demo, itsumo, bagu no sei ni shite monku iu kara chotto unzari nan da yo ne.” “Rikkoku wo horobosu mono wa rikkoku datte kidzuitenai you da ne.” “E… Shiviraizeeshon ja nai yo, Monsutaa Hantaa da yo.”)
[“Shin-kun fails a lot in MH, but he always blames it on bugs, I’m kind of fed up with it.” “He must not have realized that a country contains the seeds of its own ruin.” “Eh? … It’s Monster Hunter, not Civilization!”]