上句见：Day339
The Story of Philosophy《哲学的故事》第1章Plato第7节VI. The Psychological Solution第2段第5句：

We must begin by "sending out into the country all the inhabitants of the city who are more than ten years old, and by taking possession of the children, who will thus be protected from the habits of their parents"(540). We cannot build Utopia with young people corrupted at every turn by the example of their elders. We must start, so far as we can, with a clean slate. It is quite possible that some enlightened ruler will empower us to make such a beginning with some part or colony of his realm. (One ruler did, as we shall see.) in any case we must give to every child, and from the outset, full equality of educational opportunity; there is no telling where the light of talent or genius will break out; we must seek it impartially everywhere, in every rank and race. The first turn on our road is universal education.
浙江大学译本：（我们将看到，一位君主果真这样做了。）

解析

1、(One ruler did, as we shall see.)
（我们将看到，有位统治者真的这么做了。）

这句有效补充及验证了上句的quite possible。这句插入语直接解决了我们的疑问，同时又埋上另一个疑问：谁？