It means if. Proof:
Now, assume conjunction. Wang Niansun said: "It's just like this now."
Example: There is no other way to enjoy this with the people. Now if the king enjoys happiness with the people, then he is king. "Mencius, King Hui of Liang"
Yang Shuda commented: "This is to say that one thing is done, but to say that he uses it at the right time. Wang's training is "ruo", which is obtained from the context. I suspect that the word is still the same today. The original meaning is not the meaning of the word "ruo".
It means: the word "Jin" itself does not have the meaning of "if" or "hypothesis". But after saying one thing, when changing to another thing, it has the meaning of hypothesis and if in connection with the context. This is not the original meaning of the word today.