Plato, perhaps one of the most famous philosophers in history, lived in the IV century before Christ, in the Athenian polis of Ancient Greece, a society eternally admired for its political model that organized itself in the closest way to (the purest) democracy, that has ever existed. Although they still did not conceive equality in a horizontal way, since the separation of classes was still very clear, there was a large number of citizens who met to make decisions and vote on what concerned them as a community.

Also when it comes to justice, in these city-states, there were already extraordinary magistrates in charge of drafting laws and mediating conflicts. This concept, that of justice, linked to the achievement of harmony, will be central in Platonic philosophy, since he lived the transition from the democracy of Pericles to the tyranny of the Thirty, a turning point for Athens and deontology. The qualities of man are revealed, the virtues to be exploited in order to achieve the best possible State; Plato speaks out about prudence, fortitude and temperance.

The world has evolved a lot from then to the 21st century, but the key to a just and harmonious society may not have changed that much. From what we know about life in the Greek polis, there was also disagreement about the rulers and their way of doing politics, this is reflected in the history of thought when considering the value of the rights and duties of the people, and at the same time, the legitimate way of exercising power. For example, taking Pericles as an example, who ruled Athens in the golden period of the city, he knew how to seek what was good for everyone and with great popular support, however, Plato considered that he made the people lazy and greedy by starting to collectivize everything. The problematic always lies in the fair way of doing politics, guiding citizens towards the best achievement of their happiness, and this will remain the exact same at any time of the life of humanity.

In The Laws, he talks about the functioning of law, and how it should always seek that those under its jurisdiction always become better, an educational task on the one hand, and persuasive on the other, since he proposes that laws must always be accompanied by a preamble explaining the need or the reasons for their own existence. Let us now imagine that Plato writes another of his dialogues, this time with a lawyer from 2022. He would show him his perception of good and evil, which is actually a question of common or public good, since we all depend on everyone and it is essential for everyone to fulfill their function (in the city), under the protection of legislation that serves the interests of all and not just the powerful. The lawyer could not agree less, because today and here continues the same fight for a government that represents us all. "Laws are the means of ensuring, not only that men live, but that they live well and become as virtuous as possible."

Furthermore, the ethical term deontology that has been previously mentioned, comes from the Greek déon, which means duty. Law should never be separated from ethics, because between what is right and what is wrong, Plato goes so far as to say that the good and the just are the same thing; Laws are human’s tools for humankind, born of reason and for the purpose of personal and social improvement. Without them we would not be homo sapiens, while letting ourselves be guided by a rational duty, we approach the practice of justice, truth and wisdom.

The lawyer of the 21st century could refute Plato that the world has become very complicated, the reading of the law is much more extensive and complex to deal with the infinity of new situations that arise today. But Plato already provided a dynamic approach to law, because in his proposal of absolute Ideas, the positive law that affects the sensible world, must not be eternal but changing.