Lucretius is pretty critical of organized religion in his book (in his time, this was specifically the Greco-Roman polytheistic religion, rather than some of the monotheistic religions which have since increased in popularity). At one point, after telling a well-known classical story of religious fanaticism (the story of Iphigenia at Aulis), he famously remarks
tantum religio potuit suadere malorum
("So much evil could religion convince [people to perform]!" Some people translate religio here as "superstition". But that distinction might not have been so clear-cut in earlier times; for instance, the Vulgate actually uses "superstitiores" to render what St. Paul called the Athenians in his sermon on the Areopagus in the Acts of the Apostles. In English we usually hear that he was calling them "very religious".) Lucretius generally urges a naturalistic worldview, although it's not really parallel to modern scientific views. But he was still quite popular for this during the European Enlightenment.
One old edition of his work in my collection was published by Oxford's Clarendon Press, one of the oldest and most respected publishers of classics. It's entitled
Titi Lucretii Cari de Rerum Natura Libri Sex
which means
Six Books by Titus Lucretius Carus about the Nature of Things
I'm pretty sure that some censorware, or Internet censorship software, is going to see that word "sex" -- which is the Latin word for "six", which is the number of "books" or sections in the De Rerum Natura -- and decide to censor my web page because I must no doubt be talking about sexuality somehow. Now, I think it would be wrong to censor my page even if I did talk about sexuality, but it's just ridiculous to be censored for talking about classical authors.
There are some real-life cases where censorware misinterpreted texts in Latin or other languages and thought -- due to completely naive pattern-matching -- that those texts were sexually explicit English texts.
Q. Which one of the following passages is sexually explicit? Which one will a computer program more likely decide is sexually explicit?
Anyway, classical titles were often more functional and less figurative than modern titles. It's very usual to see a title like
[Number] Books by [Author] about [Topic]
which even suggests that the author didn't necessarily choose his or her own title. (In fact, some classical authors who wrote about their own works didn't even use a consistent name for a particular work! Many of Cicero's essays are a good example of all this.)