上句见：Day203
The Story of Philosophy《哲学的故事》的第204句：第1章Plato第3节III. The Preparation of Plato第3段第1句：

Meanwhile his efforts to save Socrates had marked him out for suspicion by the democratic leaders; his friends urged that Athens was unsafe for him, that it was an admirably propitious moment for him to see the world. And so, in that year 399 B.C., he set out. Where he went we cannot for certain say; there is a merry war of the authorities for every turn of his route. He seems to have gone first to Egypt; and was somewhat shocked to hear from the priestly class which ruled that land; that Greece was an infant-state, without stabilizing traditions or profound culture, not yet therefore to be taken seriously by these sphinxes pundits of the Nile. But nothing so educates us as a shock; the memory of this learned caste, theocratically ruling a static agricultural people, remained alive in Plato's thought, and played its part in writing his Utopia. And then off he sailed to Sicily, and to Italy; there he joined for a time the school or sect which the great Pythagoras had founded; and once again his susceptible mind was marked within the memory of a small group of men set aside for scholarship and rule, living a plain life despite the possession of power. Twelve years he wandered, imbibing wisdom from every source, sitting at every shrine, tasting every creed. Some would have it that he went to Judea and was moulded for a while by the tradition of the almost socialistic prophets; and even that he found his way to the banks of the Ganges, and learned the mystic mediations of the Hindus. We do not know.
浙江大学译本：：此时，他拯救苏格拉底的举动在当权的民主人士中引起了警觉和怀疑。他的朋友告诫他，雅典已经不安全了，他可以趁这大好机会去周游世界。

解析

这句话解释了柏拉图流亡的原因：营救苏格拉底的种种努力。
1、Meanwhile his efforts to save Socrates had marked him out for suspicion by the democratic leaders;
遭猜疑：与此同时，他为拯救苏格拉底所做的种种努力招致了民主派领袖的猜疑；
marked sb out: mark sb./sth. out or mark out sth./sb. This phrase means to show that sth./sb. Is special or different in some way

2、his friends urged that Athens was unsafe for him, that it was an admirably propitious moment for him to see the world.
流亡：他的朋友劝他说，雅典对他已经不安全，却是他出去看世界的绝佳时机。
urge: to try to persuade (someone) in a serious way to do something 敦促，力劝
She urged her son to finish the homework before 8.她敦促儿子在8点前完成作业。《新概念英语2》
admirably: admire means very good. Admirably表示“极好地，美好地；令人钦佩地”
He had a beautiful old house in Queen Anne Street, and being a man of taste he had furnished it admirably. 他在安皇后街有一所老宅子，布置很优雅，因为他是一个富于艺术鉴赏力的人。《月亮和六便士》
propitious：likely to have or produce good results 顺利的；有利的； propitious moment=the best timing
Never would there be a more propitious time to find an alternative environment to water. 因此，找一个取代水的环境的最佳时刻终于到了。《万物简史》

与此同时，他为拯救苏格拉底所做的种种努力招致了民主派领袖的猜疑；朋友力劝他，雅典对他已经不安全，却是他出去看世界的绝佳时机。