上句见：Day110
The Story of Philosophy的第111句：第1章Plato第2节II. Socrates第4段第4句：

Why did his pupils reverence him so? Perhaps because he was a man as well as a philosopher: he had at great risk saved the life of Alcibiades in battle; and he could drink like a gentleman — without fear and without excess. But no doubt they liked best in him the modesty of his wisdom: he did not claim to have wisdom, but only to seek it lovingly; he was wisdom’s amateur, not its professional. It was said that the oracle at Delphi, with unusual good sense, had pronounced him the wisest of the Greeks; and he had interpreted this as an approval of the agnosticism which was the starting-point of his philosophy— “One thing only I know, and that is that I know nothing.” Philosophy begins when one learns to doubt— particularly to doubt one’s cherished beliefs, one’s dogmas and one’s axioms. Who knows how these cherished beliefs became certainties with us, and whether some secret wish did not furtively beget them, clothing desire in the dress of thought? There is no real philosophy until the mind turns round and examines itself. Gnothi seauton, said Socrates: Know thyself.
浙江大学译本：据说德尔斐城具有非凡能力的祭师称苏格拉底是最聪明的希腊人；而苏格拉底本人则将其解释为对其哲学起点即不可知论的认同—“我所知道的唯一事情就是我什么都不知道”。

解析

这句话祭司有关苏格拉底的论断以及苏格拉底的不可知论。
1、It was said the oracle at Delphi, with unusual good sense, had pronounced him the wisest of the Greeks;
苏格拉底受赞扬：连非凡能力的祭司称其为最聪明的希腊人。
据说苏格拉底一朋友问祭司，谁比苏格拉底聪明。这个祭司说没人。这个答案让人很吃惊。因为苏格拉底一不是政治人物，二不是有钱人，三不是传统意义的哲学家（当时被认可的哲学家应该是智者）。这个答案同样让谦虚的苏格拉底惊讶，他认为“唯一知道就是一无所知”。
oracle：in old Greece, a person (such as a priestess) through whom a god was believed to speak古希腊的传神谕者，神使，宣示神谕的祭司，后引申为“先知”。
The ancient Greeks believed that they could consult the famous oracle at Delphi about their fate. 古希腊人相信他们可以向德尔福著名的神谕咨询他们的命运。
Delphi：德尔斐（Δελφοί）是一处重要的“泛希腊圣地”，即所有古希腊城邦共同的圣地。“泛希腊圣地”是一个外在于城邦政治的复杂构造，在宗教意义上为所有希腊人提供自我认识的唯一途径，据说阿波罗神庙的入口处刻着三句箴言：「认识你自己」（γνῶθι σεαυτόν）、「凡事不过份」（μηδεν αγαν）、「妄立誓则祸近」（ἐγγύα πάρα δ'ἄτη）。
with unusual good sense： it indicates the oracle has exceptional insight 非凡的洞见

2、and he had interpreted this as an approval of the agnosticism
不可知论提出：他对祭司的话而视为对不可知论的赞同。

3、which was the starting-point of his philosophy—
不可知论地位：苏格拉底哲学的起点。
starting-point：基础，起点
A pair of pretty, faded pink antique curtains was the starting point for the room's colour scheme.
一幅漂亮的褪色仿旧粉色窗帘是房间色彩搭配的基调。

4、“One thing only I know, and that is that I know nothing.”
不可知论内容：唯一知道的就是我一无所知。

据说，德尔斐的祭司非凡洞见地指出他是整个希腊城邦中最聪明的人；而他将这个解释为不可知论的证明。不可知论是他哲学的起点，指的是“我所知道的仅仅是我一无所知”。