The fundamental concept of IT! is standard low-economy fifties science-fiction: a monster terrorizes a group of people, and this situation puts human civilization at risk. In IT!, the monster murders all but one member of a mission that has landed on Mars, then sneaks on board the ship that is sent to rescue Col. Carruthers, played by the uninspiring Marshall Thompson, the lone survivor. Once on board, the monster terrorizes the crew of the rescue ship, killing them off one by one, but eventually their efforts to kill him overcome and mankind survives.
Alien follows along a very similar storyline: the ship Nostromo lands on a strange planet, where they encounter an extraterrestrial, so they decide to hightail it off of the planet and to a safer location. The alien, however, has parasitically attached himself to one of the crewmembers, in whose body he plants an egg. In one of the most intense scenes in recent movie history, the baby alien bursts out of the man�s abdominal cavity, and then scurries off into the bowels of the ship. He then eats the ship�s crew one by one, until finally our hero, Ripley (played by Sigourney Weaver) has a climactic showdown with the beast.
Scenes from IT! are recycled in Alien. In a scene from each movie, the respective monster attacks and kills a crewmember hiding, waiting for the alien in the ship�s ventilation system. In both films the body of said victim is never found, but there is also no evidence the poor guy was eaten. Both movies also include a heated rivalry between two key crewmembers; in addition, the alien is overcome when it gets flushed out of the ship through an open airlock. Other details, such as the ridiculous notions of smoking in space and the use of weapons such as flame-throwers and grenades in deep space are also repeated.
Many science fiction movies of the fifties had political messages, such as the acceptability or the condemnation of nuclear weapons, or the promotion or criticism of scientific progress, and so on and so forth. Peter Biskind, a noted movie and culture commentator, details many of the different views expressed in fifties movies in his book Seeing is Believing.
A critical theme of Biskind�s is the differing message of science fiction movies of the fifties. There are radical liberal sci-fi movies, which praise scientific advancements, and often include problems overcome by science that were otherwise unsolvable. On the other hand, radical conservative science fiction films are quick to point out the dangers of reckless scientific progress, and problems are solved by the army, rather than scientists. Then there are the centrist films, which try not to aggravate people or create controversy: a happy ending, likeable characters, and the avoidance of the truly volatile issues. IT! seems like it would fit perfectly into either of the extreme points of view, but rather it settles comfortably into the centrist mold.
Centrist films aim to reach a non-threatening, non-extremist consensus. The centrist movies of the fifties tended to hope for better days, before innocence was lost and when people were trustworthy. There was still paranoia, but it was a fear of the unknown; whatever was known could be trusted. It is thus on the essential issue of paranoia and cynicism that the biggest difference between IT! and its remake is rooted.
The crucial theme of IT! is the importance of trusting others and to avoid rushing to hasty accusations. Throughout the movie, Col. Van Heusen (played by Kim Spalding) frequently accuses Col. Carruthers of having murdered all of his comrades and fabricating a story about a flesh-eating Martian. Even though Carruthers has a sound story, Van Heusen refuses to believe Carruthers� version of the off-ship, off-screen happenings. Soon the alien starts victimizing space travelers on board the ship, but Van Heusen still won�t believe until he catches a glimpse of the monster with his own eyes. Van Heusen�s character is humbled, and even though he is still the actual captain of the ship, Carruthers becomes the de facto leader of the voyage. Van Heusen is portrayed as foolish and incompetent because of his skepticism; on the other hand, Dr. Mary Royce, a scientist on the ship, is totally trusting of Carruthers and they hit it off rather nicely, sparking a mild romantic relationship between the two of them. Royce is seen as intelligent and virtuous because of her trust, whereas Van Heusen is vilified because of his cynicism.
This is not the case in Alien, in which Ridley Scott promotes a left-wing viewpoint of paranoia and skepticism. When the Nostromo first lands on a strange planet that is inhabited by a race of aliens that would later terrorize them, only Ripley and a worker named Parker (the always excellent Yaphet Kotto) seem to be aware of the dangers of exploring an unknown environment. Their apprehension is disregarded, but their paranoia is soon to be revealed as prudent, rather than foolhardy. Much like in IT!, there is mistrust among crewmembers as well: Ripley does not trust Ash, the science officer on board who does not care about his crewmember�s well-being. In this instance, Ripley�s mistrust turns out to be correct: Ash is a robot sent by �the company� to keep the humans in line and to protect the monster so that science can study it, even if the completion of this objective means the loss of the (human) crew. Once Ripley discovers this and Parker destroys Ash, the few remaining crewmembers are free to go about destroying the alien.
Alien also contains a much different type of skepticism, a paranoia rooted in doctrine and theory, not just as a plot device. The movie seems to contain a very strong anti-science message, but upon further review it is a denouncement of authority, not technology. There is the presence of �the company� hanging over all of the occurrences on the Nostromo, but there is no classification for the company, whether it is a private industry, a guild, a political organization, or a scientific research team, or something of the sort. The company breaks the trust of its employees, sending this aforementioned message to Ash: �Priority One: Insure return of organism for analysis. All other considerations secondary. Crew expendable.� This suggests the notion that the company is somehow a scientific endeavor, but this is not clear, thus delivering an anti-authority, not anti-science, message.
There are other strong left-wing undercurrents to Alien as well that were not present in IT!. In the latter, the women on the ship literally brew coffee for the men, tend to their wounds and comfort them after attacks from the monster. The crew is also all white; not a single minority appears in the entire movie. In Alien, the two main characters are a woman (Ripley) and a black man (Parker), and Ripley is not making coffee for a man. Sigourney Weaver became a left-wing feminist icon for her role in this movie, which, even though it is a remake of a centrist film, is an extraordinarily liberal film that promotes skepticism and rampant cynicism.