[Don Jones]

It's fair to judge a translation without knowing the source language. It's also true that to know both languages makes for a deeper enjoyment, like knowing how to read music to understand more intimately a symphony.

But if we take the second rule too far, then so few would be able to comment at all and traffic at the Translation forum is thin anyway. I think it's important to keep in mind that the two types of critique of translation (by one who knows, and by the other who doesn't, the source language) are critical because

a) a translator needs to understand the source language, and

b) someone who doesn't know the source language must also pass judgment.

Point b is important. The purpose of translation is broadly, though not solely, to make available to audiences a version in their own language, the very audiences that do not know the source language. On the other hand, you need someone who knows the language to ensure that those who don't can take on trust that the version they read is a reasonable approximation. Both watchdogs are necessary.

In any case, how well did Baudelaire or Proust know English? Were they fluent? I don't think so though I could be wrong. I know Proust wasn't. Yet one translated Poe, and the other, Ruskin.