A Gate To Be Burst: "Absence of Pain"
I can't be sure which gates Lucretius had in mind, but I can suggest one "gate" that is particularly in need of bursting, as it stands directly in the way of a better understanding…
Articles at EpicureanFriends are featured presentations on important aspects of Epicurean Philosophy. They include:
For a presentation of many details of Epicurean Philosophy assembled from a close paraphrase of passages of the ancient texts, see the slides, text, or video below. Each passage contains a citation to the text or texts from which the point is taken. For prior versions and for a discussion of this material go here.
The Current Version of The Text Is Here.