The main exponents of natural law during ancient times concerning the development of natural law spanning 500 years BC are as follows: –
Heraclitus (530-470 BC)
The notion of natural law was evolved by Greek philosophers in the 4th century BC. Heraclitus was an earliest Greek philosopher who emphasized the three main characteristics of the law of nature: –
Socrates (470-399 BC)
Socrates was a big fan of the moral values and truth. He was of the view that like natural physical law, there is a natural moral law. It is due to this human insight that a man has the capacity to distinguish between good and evil and is able to appreciate moral values. Therefore, according to Socrates, virtue is knowledge and anything that is not virtuous is misdeed. The reasonableness of specific law is judged by human intuition and only those laws should be considered proper that are according to the principles of law of nature and are supported by human reasoning.
Plato (427-347 BC)
Plato was the disciple of Socrates. He took the philosophy of natural law further through his concept of the ideal state. According to him, justice consists in ordering the life of man through reason and wisdom and in motivating him to control his passion and his desires. Therefore, the laws of state are the pale shadow of an absolute concept of perfect laws against which man-made laws are measured.
According to Aristotle, man is part of nature in two ways. First, he is created by God. Second, he has an insight and a reason to articulate his actions. He defined natural law as reason that is not affected by desires, it embodies the fundamental principles of justice and morality which have universal validity regardless of time and place. But Aristotle categorically declared that the positive law which is contrary to the principles of natural law is invalid. Aristotle suggested that the ideals of natural law emerged not from the human mind but from the human consciousness and, thus, they are much more precious than the positive law which is a result of the human mind.