It roughly means: Desire or ambition, going where they like, come to them anyway. Just don't ask me what "they" or "them" refers to here. It could be the "passion or conquest" or it could be the swans, or something else. And even then, what is it really trying to tell us? I think it's mostly nonsense for the sake of sounding poetic. It's not so much trying to deliver a serious message. Personally I tend to ignore literature like this.