This is a spectrum allocating major political philosopher (Ethical Philosopher) on according to their thought on the world and the moral judgement.
The vertical axis is the objective v.s. subjective scale which measures whether the moral judgement is based on an objective measure (coming from outside human-beings' emotional feelings and a psychological matter) or the moral judgement is merely a psychological matter so that no absolute objective moral guide line is possible to exist.
The horizontal axis is the non-natural v.s. natural scale which measures whether the alternative better world can be created and the human soul can evolve to become better or the nature of human-beings is permanent and hardly changes.
1. In Antiquity and Medieval:
First of all, the classical example of comparison between political philosophers is the comparison between Plato and Aristotle. There is no doubt to say that the comparative study of philosophy started from Plato v.s. Aristotle, and all the comparative studies of philosophy cannot ignore the debate on Plato v.s. Aristotle. Meanwhile these two philosophers existed in the same time period, one of these two has a totally different ideology from the other.
Plato is the most notable objectivist and non-naturalist in the Western philosophical world. Plato believed there is an ideal community (the utopia) can exist, and existence, morality, and mind-set of human-beings can evolve to be better (by means of how Plato defines what is better and worse). He also claimed that there shuold be a strong, absolute, universal, and permanent moral principle which shall guide human-beings to evolve.
Plato also argued that a supreme (as he defines) group of human-beings should be the leaders who quickly learn and understand the absolute moral principle and overcome from the human nature (evolve from the real state to the ideal state). He also claimed that these leaders should guide the other inferior human-beings, who are difficult to evolve to the ideal state.
By contrast, Aristotle questioned if human-beings are able to find the absolute and permanent moral principle guiding how individual human-beings should be. Aristotle stated that the value of morality varies across the different time periods, places, and cultures. Aristotle also claimed that human-beings is naturally able to guide themselves to the optimum way of living in their community. "Human-beings are naturally social, and political-beings" is his famous quote which denotes that individual human-beings themselves should constantly discuss and evaluathe their moral decision, and then decide what is right and wrong at the current time, place, and occasion.
Aristotle contradicted Plato because Aristotle argued that human's characteristics constantly changes over time, place, and occasion. Therefore, even though some individuals have a strong enthusiastic altruism, ability to guide the other individuals to the principle, and a deligent hardworking spirit, these individuals can be corrupted when they start to hold a power to control over the others. Furthermore, Aristotle also clarified the fact that all the communities in the world have different needs, and all the individual human-beings' opinions have to be represented. Thus, there shuold not be a few number of individuals controlling over the others because there is no absolute measure to define which is better and worse.
Only the universal objective principle Aristotle mentioned was that "human-beings are naturally social". This quote states that, even though the moral value varies across time, place, and occasion, all human-beings in any parts of the world are essentially same. He affirmed that all human-beings must live together. Otherwise, human-beings turn up to become a beast (savage). This is the aspect that Aristotle was one of the first remarkable philosophers who put emphasis on the cosmopolitanism. As all human-beings can nagotiate each other to derive the optimum solution to be united, they can live together with peace and unity.
This philosophy states that the world is constantly changing, and human-beings can be unified when they nagotiate each other. The problem of this philosophy is that it does not clarify how the world changes, and restrict the possibility of new discoveries because humans' perspective to only focus merely on how the things surrouding them are. This problem disrupts human-beings discovering and inovating new things and thoughts and beciming sceptical about how the real world is formed. Furthermore, human-beings from the different culture may bring further conflict rather than unity. When both parties are considered equally right and wrong, they may never compromise their own wants and tolerate any negative feeling (E.g hatred, stereotpy, mis-understanding, and biological and emotional sense) about the others. Thomas Aquinas, who adapted Aristotle philosophy into the primative Christianity to reform Christianity be more familiar to the commoners, stated, on the top of the human-naturality, there is a God's divinity as the "unmovable mover" which is the principle, denoted by Aristotle, which is only a universal natural law but too abstract to define. Aqunas's philosophy developed Aristotalian philosophy to be more clear and judgemental. However, Aqunas's philosophy still restricted the possibility of descovery and inovation.
At this point, Platonian philosophy has a stronger advantage because Plato put emphasis on need of the absolute objective judgmental tool measuring which individual human-beings are right and wrong.
However, these classical philosophers had never answered to find whether or not it is possible to find an objective moral measure and principle within the human-nature. Plato and Augustine, the founder of Platonistic Christianity, definted an objective moral guideline is not able to be measured by natural human-beings so that it should be created by a non-natural supreme-being such as an idea or a God. On the other hand, Aristotle and Aquinas remained the political philosophy (ethics) to be very limitted on the world we can see now so that there is no place for deduction which forecasts the past and the future. Platonist focuses on the unreal world whereas Aristotlean only focuses on "now". Both philosophy lack the consistent and dynamic analysis of how humans and their community can change.
In addition, there is a question by some of the modern philosphers which asks whether or not it is possible expect human-beings to be virturous enough to keep themselves ethical and unified constantly. These modern philosophers criticised that both Plato and Aristotle were too optimistic about human-beings, and so contradicted there cannot be any universal objective moral (ethical) guide line like what both Plato's Idea (Augstine's God) and Aristotle's Social and Political Human-beings (Aquinas's Divine Law).