Interpret Socrates quote?

I think he meant people's feelings, and that they are subject to change....

(rest of quote) ... so judging things ("A system of morality") according to your feelings, or society's opinions, etc...("relative emotional values")...

.. is not a good idea, because, well... opinions change over time. People are often fickle, and if not, they at least change their opinions/beliefs/etc, and oftentimes actions, after learning of new things (not necessarily education, just things they didn't know before).

(the change stuff = "nothing sound in it")

(People are biased. Everyone is, to some extent. = "nothing true")

Overall, I think he's trying to say (not in the question, but it makes it clearer for me XD) that for people to agree that feelings (including opinions, beliefs, etc) are "true" and build upon that... that if people do that, their "system" is doomed to fail ("mere illusion").

If a individual won't be able to connect with what they are examining, then the message is lost upon them. while you're examining something like a infant's e book, the message is exceptionally no longer ordinary to pass over. while you're examining charles dickens or shakespeare (particularly shakespeare), in case you could no longer connect with the words, the literature turns into gibberish. it rather is a waste of time using fact it merely turns right into a chore and the excitement and mind's eye is lost.