The classics ( up to the XVIIIth century) believed that beauty is an objective matter, and that there are rules to attain it, based mostly on the imitation of nature, the depiction of human nature, and a certain aspiration for truth. At the same time many philosophers doubted that there is real beauty: the British "sentimentalists", e.g Hutcheson, Shafestbury, Smith , Hume and others believed that beauty ( like goodness) is a matter of expression of feelings. Nevertheless they thought that there could be agreement on such aesthetic and moral feelings ( see for instance Hume's famous essay "On the Standard of Taste". Why is it that today we have lost not only confidence in real beauty as an objective fact but also in the possibility of agreeing on aesthetic standards ? This is a long story of course, which ends up in today's post-modernist and relativistic themes. Not everyone agrees with that.
I recently read the book by the XVIIIth century painter William Hogarth, The Analysis of Beauty. Although he painted sometimes horrible scenes, he depicted human nature and believed that there are rules for crafting beautiful paintings, which he describes in the book. They are certainly not God given, and they imply a lot of work. Are they relative to his age ? I do not think so. Was his craft purely time relative? The success of the Hogarth exhibits in Paris and London last spring shows that there is permanent admiration for his work. I'm inclined to think, as the British philosopher of art Anthony Saville , that beauty stands "the test of time". So if the judgement about the beauty of your poems resists, and if you can at some point teach the rules of your art, you pass the test.