I've been wrestling with the game theories being tossed around that the line "The Cake is a Lie" is the entire basis for the Portal game, and have been thusfar rewarded for my speculation while venturing into Portal Deux (obvious omission for those who haven't gotten that far yet). To begin, pre-modernity held the ideals that the journey is far more important than the result, and tailored a mind-set specifically for that (queue in St. Augustine, John of Salisbury, Aristotle, and other big names). The key principle holding all these names together is that the prize is achieved by having the purest journey possible, and being the best at what you're designed for. This obvious application of the phrase "designed for" in reference to the portal series is that the test subject is designed to make it through a series of objectives and make it through said objectives efficiently, at which point you will be rewarded with "cake". This, however, is where the pre-modernity facet ends, during the refusal to burn in the fires of which Glados has designed for you.
We are not supposed to question our fate, but be rewarded for being the perfect subject...a lesson that the protagonist of Portal Un tosses into the proverbial fire by escaping the real one. From here on, the protagonist has broken the mold, freeing herself from the confines of the Great Chain of Being, and has become her own self, a modernist. This modernist continually fights the established order, culmulating into a defeat of the Morality Core of Glados, which, if aperture science truly is related to the half-life scientific structure in which Black Mesa is a part of (alluded to in the ending credits musical masterpiece), was created by a pre-dominately male team. Yes, yes, this is a leap of logic, but I challenge you to go through the Black Mesa research facility in Half-Life one and find a single pair of double X-chromosomes. The reward would have been the cake in which Glados has designed in pre-modernity, afterlife cake. The modern journey takes that cake and turns it into the proverbial oyster of opportunity at the end of Portal, in which the protagonist is free, only to be dragged back down by the system and taken again by the lovely disembodied voice of our favorite robot. I don't use the word sociopath in lieu of robot specifically because sociopath indicates some semblence of human-esque emotion, emotions that glados glady lets you know she doesn't really have during the co-op campaign of Portal Deux.
In closing, my theoretical journey has the protagonist exemplifying all that is best of both pre-modernity and modernity, a blending of the two that results in both a pure individual and an individual that isn't incapable of preserving herself against a blatantly harmful and corrupt institution.