上句见：Day65
The Story of Philosophy的第66句：第1章Plato第1节The Context of Plato第4段第2句：

In 490-470B.C. Sparta and Athens, forgetting their jealousies and joining their forces, fought off the effort of the Persians under Darius and Xerxes to turn Greece into a colony of an Asiatic empire. In this struggle of youthful Europe against the senile East, Sparta provided the army and Athens the navy. The war over, Sparta demobilized her troops, and suffered the economic disturbances natural to that process; while Athens turned her navy into a merchant fleet, and became one of the greatest trading cities of the ancient world. Sparta relapsed into agricultural seclusion and stagnation, while Athens became a busy mart and port, the meeting place of many races of men and of diverse cults and customs, whose contact and rivalry begot comparison, analysis and thought.
浙江大学版本：在这场年轻的欧洲对阵日渐衰老的东方帝国的争斗中，斯巴达提供了陆军，雅典贡献了海军。

解析

这句话说明两个城邦在希波战争的角色。
In this struggle of youthful Europe against the senile East, Sparta provided the army and Athens the navy.一场老旧势力之战争，不同城邦提供不同类型的军队。这里两个对比，一是youthful Europe对senile East，另一个是斯巴达与雅典。这次讲希波战争，以两个洲的立场来讲的，一个年轻的欧洲，一个是年迈的东方。前面用的是具体的主体，侧重了侵略与反侵略的性质。两处不同的表达方式显示了语言的灵活性。
senile：showing a loss of mental ability (such as memory) in old age
As if everything Ove had said was nothing more than the inarticulate raving of a senile old man.就好像欧维所说的一切不过是老年人的胡言乱语。《一个叫欧维的男人决定去死》

在这场年轻的欧洲和年迈的东方之间的对战，斯巴达提供了陆军而雅典提供了海军。