Those bits of ancient advice are worth considering as two Hollywood studios hope to launch film franchises that use Greek mythology as the unlikely premise for popcorn entertainment. 'These are the stories that began storytelling in many ways,' director Louis Leterrier said a few months ago on the London set of his 'Clash of the Titans,' the Warner Bros. epic that arrives in theaters in March with Sam Worthington as Perseus, Liam Neeson as Zeus and Ralph Fiennes as Hades. 'These are tales of adventure that endure. These stories are who we are.' True, which lives up to the 'Know thyself' advice. But as for that second suggestion, the one calling for limits, well, Hollywood has never been known for moderation. 'Clash of the Titans' arrives in theaters on the winged heels of 'Percy Jackson & the Olympians: The Lightning Thief,' which also has mighty Zeus (Sean Bean), the nefarious Hades (Steve Coogan) and the other gods of grand Olympus, although it brings them to modern-day Manhattan where they meet the title character, one of the most popular heroes at the bookstores in recent years with the best-selling young-reader novels of Rick Riordan. No surprise, the makers of both films are eyeing each other with some anxiety. 'You can't ignore it,' said 'Percy Jackson' director Chris Columbus while taking a break from post-production work in San Francisco on the film that opens Feb. 12 and, for Fox, has been circled as a potential 'Harry Potter'-style multiple-film property. 'They are two completely different pictures. But I'd be a liar if I said that I'm not fascinated by everything they're doing. In today's version of Hollywood, you have to be aware of everything else that's going on around you. It's just kind of foolish to put yourself in a bubble and pretend it's not there.' It's interesting that Hollywood is once again looking back to Greece and the Roman Empire for adventure tales and, in the cases of 'Clash' and 'Percy,' special-effects fantasies. Just as 'The Lord of the Rings' and 'The Chronicles of Narnia' were pulled from the bookshelf for their potential in this digital-effects era, Columbus said the thunderbolts of Zeus and the pits of Tartarus are camera-ready for the 21st century. 'The world of Greek myth really hasn't been dealt with, on screen, in a long time, at least not in terms of a big blockbuster motion picture,' Columbus said. 'It's exciting to think about. At least it is for me.' 'Percy Jackson' stars 17-year-old Logan Lerman ('3:10 to Yuma') as the title character, a troubled youngster who (like a certain boy-wizard) discovers he has a magical heritage and then teams with his young friends to fight the dark forces aligned against him. Columbus directed the first two 'Potter' films and was brought in by Fox with hopes that magic lightning can strike twice. 'Clash of the Titans' is a familiar brand name to fans from the 1981 movie of the same title and, like that film, this new model is more about an adrenaline adventure than meticulous scholarship. Leterrier (2008's 'The Incredible Hulk,' 'Transporter 2'), for instance, was playing with the idea of presenting Pegasus as a black horse with webbed batlike wings instead of the iconic white steed. He and his star, Worthington, have already discussed the possibilities of a sequel, and Warner Bros. has high hopes for the movie. The films follow a surge in more traditional sword-and-sandal movies in recent years. The decade began with 'Gladiator,' which won the Oscar for best picture, and it was followed in 2004 by both 'Alexander' and 'Troy.' It was the 2007 hit film '300,' though, that truly captured the attention of Hollywood executives with $456 million in worldwide box office off a $67-million budget. The Zack Snyder film, the highest-grossing March release ever, was based on Frank Miller's graphic novel about King Leonidas and his doomed army of Spartans. Miller is preparing a follow-up titled 'Xerxes,' which begins about 10 years before the events of '300,' and Snyder has expressed interest in it as a film property as well. 'It's the battle of Marathon through my lens,' Miller said. 'I've finished the plot and I'm getting started on the artwork.' Miller said he is not surprised Greece is resurgent in Hollywood. 'Every generation returns to ancient Greece because, well, the stories are so damn good,' said the artist, who also directed 'The Spirit' in 2009. Miller said that during his research trips to Greece he realized that the myth and history overlap begins to blur, which adds to the storytelling allure. 'The fact and the myth are inseparable and, believe me, when you go sailing for a while in the Aegean Sea, you start believing in Poseidon.' The success of '300' was a likely inspiration for the new series 'Spartacus: Blood and Sand,' which premieres Jan. 22 on Starz (it even co-stars Peter Mensah, whose character died memorably in '300' when he was kicked into a pit by Leonidas). The empire was last seen on a regular series in 'Rome,' the HBO series that won seven Emmys during its 22-episode run and is now, according to star Kevin McKidd, ramping up for a feature with creator Bruno Heller ('The Mentalist') finishing the screenplay. McKidd, known to 'Grey's Anatomy' fans as Dr. Owen Hunt, is taking his experience in 'Rome' to 'Percy Jackson,' where he plays Poseidon, the estranged father of Percy. 'It's a tricky thing in this movie,' the Scottish actor said. 'I do modern times right now on `Grey's,' and on `Rome' I played a character from antiquity. With this film, you have these gods who scale themselves down to walk the streets of modern Manhattan. But you think you have to play it differently because you have these classical texts. So how do you strike the balance? Chris Columbus helped us define it. These gods can be contemporary and act in a contemporary way. It's a great thing because you can hit the ground running with emotion instead of putting on this classical mask as you would on stage.' The classics of Greece never really left us, of course, when it comes to theater; just note the production of Euripides' 'Medea' with Annette Bening this year at Freud Playhouse at the University of California, Los Angeles. Other pop-culture ventures of the moment take the influence of Greece into unexpected directions. One of the most compelling comic books right now, for example, is Vertigo's 'Greek Street,' written by Peter Milligan, which transports Greek myths to contemporary London. The tales of Cassandra (called 'Sandy' here) and Oedipus (now simply 'Eddie') play out in familiar rhythms but with a backdrop of Milligan's gritty Soho. Then there's the acclaimed SyFy series 'Battlestar Galactica,' which had plenty of references (characters called Apollo, Athena, Cassiopeia) and planets named after the Greek zodiac. The tales of the 'Battlestar' universe continue on Jan. 22 with a spinoff series called 'Caprica' and there are plans for a 'Battlestar' feature film by Bryan Singer. Hollywood isn't limiting its star search to the Greco-Roman gods. Marvel Studios and director Kenneth Branagh are under way with 'Thor,' based on the Norse god of thunder as imagined by Jack Kirby, Walt Simonson and, more recently, J. Michael Straczynski in the pages of Marvel Comics. Are the old gods still viable to the young moviegoers who made 'Transformers: Revenge of the Fallen' the highest-grossing film of 2009? On the set of 'Clash,' Worthington dismissed the idea that ancient epics can't be of the moment. 'Look at this world,' he said, nodding toward the set of the river Styx. 'We're not exactly going by the book. The armor we wear is very futuristic looking. It's not dated to a period of time in a history book. This is a story with winged horses ... but what we're doing, we have to have a modern take on it, to make it relevant to our audience. This isn't like a Ridley Scott kind of thing, where every minute detail has to be an exact replica. We're making a fun kind of romp.' The original 'Clash' starred Harry Hamlin, Laurence Olivier and Burgess Meredith, but the most memorable performance was the stop-motion animation by effects pioneer Ray Harryhausen. Those effects look quaint now, but they captured the imagination of many youngsters, including an 8-year-old Leterrier in his native France. Leterrier was resistant to the idea of a remake, but he came around after considering the wide range of gods and creatures who were untapped in the first picture. The new film, from the screenplay by Phil Hay and Matt Manfredi, follows the journey of Perseus, the son of Zeus and a human mother, as he becomes a reluctant volunteer in the building conflict between his father and Hades. The film, like the original, is an amalgam of Greek myths, and, again, a centerpiece is the showdown with Medusa, the creature with serpent tresses. This time, Medusa's lair has staircases and walls that run off in different directions, like an M.C. Escher madhouse, since she can slither up surfaces. 'It's amazing,' Leterrier said of the work by production designer Martin Laing. But will it be enough to set 'Clash's' Medusa apart from the one moviegoers will have already seen in 'Percy Jackson'? Columbus smiled at the question. 'We're a good, solid five weeks ahead of the release of `Clash,' so we will have succeeded or failed at that point,' Columbus said. 'I'm very, very confident about our characters, our performances and our creatures. And I'm telling you, when you see Uma Thurman as our Medusa -- well, you've never seen anything like it. It's pretty spectacular. It's something you've never even dreamed of.' 