Why use 10 kanji when 4 will do?

I received an email from some friends in Ishinomaki, Japan this week. The phrase they used to describe how people are finding the strength to rebuild after the tsunami was 弱肉強食. This can be loosly translated as "survival of the fittest"

Since I received their email earlier this week, I have been looking into 四字熟語 or 4 character idioms. I like how neatly they convey a meaning or message in just 4 characters. I have shared some below and you can find others on Wikipedia

一攫千金 ikkakusenkin (ichi one + kaku grasp + sen thousand + kin gold)making a fortune at a stroke. (Origin: Chinese classics)

美人薄命 bijinhakumei (bi beauty + jin person + haku thin + mei life)A beautiful woman is destined to die young.; Beauty and fortune seldom go together. (Origin: Chinese classics)

酔生夢死 suiseimushi (sui drunken + sei life + mu dreamy + shi death)idling one's life away; dreaming away one's life accomplishing nothing significant (Origin: Chinese classics)

羊頭狗肉 yōtōkuniku (yō sheep + tō head + ku dog + niku meat)crying wine and selling vinegar; extravagant advertisement (Origin: Chinese classics)

悪因悪果 akuin'akka (aku bad/evil + in cause + aku bad/evil + ka effect)An evil cause produces an evil effect; Sow evil and reap evil. (Origin: Buddhist scriptures)

会者定離 eshajōri (e meeting + sha person + jō always + ri be separated)Every meeting must involve a parting; Those who meet must part. (Origin: Buddhist scriptures)

一石二鳥 issekinichō (ichi one + seki stone + ni two + chō bird)killing two birds with one stone (Origin: English proverb)

異体同心 itaidōshin (i different + tai body + dō same + shin mind)Harmony of mind between two persons; two persons acting in perfect accord 

我田引水 gaden'insui (ga own/self + den field + in draw + sui water)self-seeking; feathering one's own nest