Interpreting the Catalyst: A Mass Effect Analysis, Part 1
A billion years ago, the galaxy was ruled by the Leviathans, a race of giant and apparently aquatic creatures that had the ability to telepathically control the lesser species of the Milky Way. According to information revealed in Mass Effect 3’s “Leviathan” DLC, the species built an empire of sorts, acting as gods over their thralls and protecting them in exchange for “tribute” — whatever that means in this context. While ruling over the other advanced sentients of the time, the Leviathans were somewhat detached — they had concerns the thralls couldn’t understand, or so they claimed (video 2).
The Catalyst decided the best option based on the information it had collected would be to harvest advanced civilizations by collecting their biological makeup and memories.
At some point, the Leviathans took note of a handful of incidents in which thrall species would create synthetic helpers that would eventually “rebel” and drive them to extinction. So they built an “Intelligence” by some means — we’ll assume it’s strictly artificial, but likely unprecedentedly advanced from the outset — which they tasked with figuring out how to solve this conflict between synthetics and their organic creators. This Intelligence watched and collected data for a while, and tried out some ideas here and there, before eventually implementing a version of the “Zeroth Law” in a really hardcore way (videos 1 and 2).
The Zeroth Law comes from Isaac Asimov, author of the Three Laws of Robotics. The Zeroth Law is a mutation of Asimov’s First Law of Robotics — a robot shall not injure a human being or by inaction allow a human being to be harmed — that gives precedent to society as a whole over the individual person.* So the Intelligence, which would become the Catalyst, decided the best option based on the information it had collected would be to harvest advanced civilizations by collecting their biological makeup and memories — their essence, as the Reapers say — into a synthetic-organic hybrid machine (as seen at the Collector base in Mass Effect 2). The Catalyst started with the Leviathans themselves, which it turned into the Reaper known as Harbinger (video 2), the primary antagonist of Mass Effect 2. How it accomplished this is not known, but likely the element of surprise helped.
The Catalyst and its Reapers would then periodically harvest whatever species achieved interstellar flight, ideally before that species could build robots sufficiently advanced enough to wipe them out. The methodology used evolved over time; for example, the mass relays and the Citadel station were created by the Reapers and the Catalyst some time after they began their cycle of harvests as a means to increase the efficiency of the process (video 2). By leaving them out there for young species to find, the relays and the element zero that powers them would become the basis for their future tech, and the Citadel, located at a hub of relays, would be a natural and convenient capital for any galactic government — thereby leading new civilizations down the path the Reapers dictate (video 3).
The Reapers themselves are intelligences as well, as the organic material one contains was propped up into some sort of group consciousness when it was created (video 3). That’s not something I can explain, but one would assume that this is not unlike Shepard still being, you know, Shepard, after being literally dead for a while before Cerberus started the Lazarus Project at the beginning of Mass Effect 2.
The Reaper consciousnesses weren’t self-contained, though, as the Catalyst incorporated all their knowledge into itself as each one was built (video 1). Each new Reaper, it stands to reason then, would alter the Catalyst’s mindset moving forward as it attempted to find a better solution than the harvests.
The Leviathans do not, however, think the harvest cycle was the ultimate solution, echoing the views of the Catalyst itself.
Meanwhile, the Leviathans had not been entirely wiped out, as is revealed in the “Leviathan” DLC. Some found a way to survive, and those Leviathans stayed hidden and kept the species going into the present day. At some point in the past, they even managed to kill a Reaper, the shell of which the Batarians called the Leviathan of Dis, which serves as the instigator for “Leviathan”. Otherwise, the Leviathans mostly just sat back and watched in begrudging approval as the Catalyst attempted to carry out its mandate. The Leviathan with whom Shepard speaks in Mass Effect 3 says they do not, however, think the harvest cycle was the ultimate solution, echoing the views of the Catalyst itself (video 2).
Notably, the Leviathan that Shepard meets refers to the harvest as an “experiment,” rather than a “solution,” as the Catalyst calls it. It also says the Reapers are its enemy, but is reluctant to get involved with the war despite the Leviathan’s ability to take down Reapers very effectively, as they demonstrate on both the Leviathan of Dis and the Reaper chasing Shepard during the “Leviathan” DLC. One also declares very confidently that any other Reapers that trespass on the planet they occupy will become their slaves. Based on these displays of power, it seems the Leviathans could possibly win the war on their own, but they won’t. They want to see what happens, as they know the harvest is not the Catalyst’s endgame; “Until the Intelligence finds what it’s looking for, the harvest will continue,” the Leviathan tells Shepard (video 2).
*This isn’t to say the Catalyst is operating under the Three Laws; it’s more of a good parallel example or inspiration (as other Asimov works are, we’ll find). The Catalyst’s choice to fulfill its mandate to preserve life by destroying advanced civilizations is a perceived deviation in the same way the Zeroth Law is a perversion of the First Law of Robotics.