In this research, it is found that the criteria of the ethical judgment in both Plato’s Philosophy and Theravada Buddhist Philosophy constitute both similarity and differences.

Plato’s ethical judgments criteria are based on human beings’ reality covering both dimensions of “individualism” and “collectivism” according to the moral virtues of human rights, independence, fraternity, equitability, and fairness which belongs to a human being who is possessed of reason and intellect.  Plato’s virtues are divided into four types of harmony:- 1) wisdom, 2) bravery, 3) moderation, and 4) justice. These 4 virtues are considered as merits for individual and social governance that is in search of virtuous justness, socialization, mercifulness, generosity, and peacefulness under the social regulations and rules.

On the other hand, the criterion of judging the goodness in Theravada Buddhist Philosophy is of the principle in carrying out the livelihood in the societies with the ultimate life goal. It is an idealism based on the personal act which can be judged as good, bad and neutral to enable the people to be helpful to one another very well in virtuous livelihood. The Theravada Buddhist Philosophy, thus, sets up the system of the criterion of judging the goodness at 3 levels namely:- 1. The level of Five precepts,  2. The level of the 10 paths of meritorious action and,  3.  The  level of the eightfold path.

The criteria of ethical judgments in both Plato’s Philosophy and Theravada Buddhist Philosophy focused on the reasonable and intellectual acts including sensuous feelings which constitute three different levels:- 1) precepts, 2) morality and 3) ethics. Thus, the criteria of judging the goodness in these two philosophies are similar and can be summarized into the following five viewpoints; 1) The viewpoint of the volition and the reason which are the basic constitutions of criterion of judging the virtues, 2) The rules of freedom based on Plato’s Philosophy and Theravada Buddhist Philosophy, 3) The morality based on Plato’s Philosophy and Theravada Buddhist Philosophy, 4) The virtuous criterion and motivation based on Plato’s Philosophy and Theravada Buddhist Philosophy, and lastly 5) The viewpoint on universality and human values based on Plato’s Philosophy and Theravada Buddhist Philosophy . However, according to both philosophies, there are differences in the intention and wisdom in convicting what beings’ act is good or bad, righteous or evil.

However, there is one special difference in criteria on virtues between Plato’s Philosophy and that of Theravada Philosophy. That difference is the renunciation of defilements according to Theravada Buddhist Philosophy, but in Plato’s Philosophy, it is not taught to forsake the lustfulness absolutely (divine morality governs the evil act, and directs the human beings to behave in virtuous ways, whereas Theravada Buddhist Philosophy teaches human being to be away from all passions and lustfulness absolutely. The idealism is seen as the ultimate virtuousness for Plato’s Philosophy, which it can be only achieved when human being passed away, but those who are alive are only learners. Conversely, Theravada Philosophy believes that the human beings are actualized to achieve the ultimate virtuousness either when they die or in future lives. Plato’s Philosophy believes that idealism is a supernatural plane while Theravada Philosophy regards the eight ways to Nirvana which are:- Right View, Right  Thought, Right  Speech, Right  Action, Right Livelihood, Right Effort, Right Mindfulness, and Right Concentration. To achieve the Nirvana, all these righteous conducts must be in harmony and accordance. The idealism in Plato’s Philosophy is that in achieving the self-actualization; the human beings must commit good conduct from the lower level to the top or ultimate level, all of which are the virtues appearing in characteristics and aesthetics in everything spiritually and in existence, including becoming a center of mind purification. The spirit of the dead people will there be the integral part of the ultimate idealism.