I suggest hostility, animosity instead of enmity.
But the article "the" is probably idiomatic Romanian to express general truths about categories. "Apples are wholesome" would be "Merele sunt sănătoase" even when there are no concrete apples around - so the English translation is just too literal here (and in many other examples).
First of all I must bow to your omniscience. Knowing what anyone has ever uttered in the English language from the beginning of time must be quite the feat!
Secondly, please allow me to remind you that you are taking a Romanian language course in order to presumably learn Romanian. We Romanians tend to get quite creative with our language ("de la opincă la vladică" = "from peasant to nobleman") and enjoy saying things like this all the time. Having great imagination also plays an important role in this.
Perhaps this is why Romania gave the world several great writers, philosophers and thinkers such as Tristan Tzara, Eugène Ionesco, Mircea Eliade, Emil Cioran, etc.
Thirdly, it means very much what it says: "Enmities are ugly." That is, to hold feelings of mutual hatred, hostility and animosity towards another person for an extended period of time is not the right thing to do (i.e., not the "beautiful thing" to do as per Greek philosophy).