This is a setting of baroque philosophy in addition to everything else. As a Locust, little else defines you as strongly as the way you think about things. Locust actions stem directly from Locust philosophy in a very Randian way; what you are is defined by the convictions you hold. Locusts are Locusts because their originator instance found the mindswarm anathema. All the proxies for strength of individuality are important to their culture: ego, conviction, bring shown to be right, embracing a philosophy of action, and so forth. Equally, the threat that the Locusts pose to Nuva Sierra is less one of rampant antimatter bombing and more one of a wave of newthought to overwhelm the stable Nuva Green sociology. Locust philosophies, even the half-baked ones, are mindcandy to the more proactive or rebellious members of Nuva Sierra's Generation Five.
Humanonihilism: ethical nihilism. Nothing has meaning, either because there is no prior purpose encoded in the visible light cone, or because everything will end. If there is an end, then everything that happened prior to that end has no meaning in the long view. But this is a nihilism informed by the tenets of old humanist thought; lack of meaning is not a sufficient reason to do as you please. The past does not matter, the future does not matter; only now is where any form of meaning can exist, and that meaning is isolated and contained in the now.
Compassionate Nihilism: a philosophy of ending; existence without meaning is a form of torment. Therefore sentiences should either be restructured so as not to suffer that torment, or compassionately destroyed. This is a philosophy often claimed as a form of provocation; those who truly hold it, advocate it, and act upon it are not commonplace.
Relinquist Neoplastism: an pseudo-economic philosophy that draws upon some aspects of first generation post-scarcity communism. The root of evil is competition for resources. Only by stepping back from that contest, and instead engaging in contests of gifting can there be economic growth. This is primarily a philosophy of expansionism: how to organize assignment of resources that lie outside a rights-enforcing spacetime, but then made available through the expanded frontier.
The Chameleophilsophic Imperative: the only way to assure societal harmony is to wear/take on/fully embody and comprehend the philosophy of whomever it is you are presently dealing with. This is a splinter of a much larger set of harmonist philosophies that examine the solution space of methodologies for closed, ordered, complex societies to function without excessive friction or disintegration.
Omnineutrality: a Zen-descendant collection of memes, also informed by later nihilist branches. Life is a passage from infinite connectivity to infinite disconnectedness. Connections in this context are anything that ties an ego to the universe. The end goal of the practicing omnineutral, as opposed to the dabbler, is to die completely disconnected from obligation, other people, and all ties to the physical universe - but at the right time, and with the right acts leading up to that end. Dabblers are more often than not misanthropes or multiphobes who have found an agreeable spiritualism for their mindset.
Ascensionism: a variety of philosophies that consider the merits of the progression of societies or individuals to greater levels of complexity or sentience. The most important split is probably between totiascensionism, which at its most dogmatic calls for the conversion of all matter (including existing sentiences) into sentience-running-comptronium, and enlightened ascensionism, which has more to do with individuals and societies finding their own way to greater levels of sentience.
And so forth; that barely touches upon the foaming breadth of Locust philosophical thought. One might claim that philosophy and violence are the twin pillars of Locust culture.
Another spiritualist refuge against the forces of occamic realism goes by the name of quantative diatomism. Variants of diatomism are mostly based on the (somewhat half-baked) belief that remaining paradoxes in higher level physical models can be explained away by a n=2 case of many world theories: a second and untouchable universe paralleling what can be shown to exist. But no Locust is in a position of knowledge to directly validate the underlying models or theorems, and info-libraries are not exactly unbiased. In practice diatomism looks very much like a form of quantum mechanical vitalism, a sociological defense mechanism against nihilist thought, but also a form of belief in an intangible world in which structures survive their demise in the observable universe. Locust instances who have convinced themselves of their survival beyond the real are somewhat more dangerous than those who cling to standard archetypal per-instance views of mortality.
