Consider Milton in his Areopagitica as a moralist?

In Areopagitica, a classical oration for the liberty of writing we find the basic principles of Milton's attitude to religion, politics and society more than in any other prose-writings. It is written with all seriousness as the subject needs. Within the limit of a pamphlet, Milton writes about the very foundation upon which the noblest and greatest human life rests. 

Milton was a man of solid morality. Though he was a puritan, he raises himself above the narrow outlook of Puritanism. The puritans claim to be moral in the pursuit of life but Milton does not find it adequate to be an ideal man. Their shortcomings and weaknesses are brought home with genuine zeal. He writes what he believes and he acts what he believes. No sort of partisan interest could deter him from speaking what is true. Without fear or favour, he goes on to say what the Parliament failed to take into consideration. Here lies the strength of his morality. The man Milton does not differ from the writer Milton. With Socratic courage, he points out the defects of Parliamentary resolution and seeks redress of it while he does not forget to praise it for the good part of the order. 

The basis of true morality is tolerance and self-criticism. Milton lays great importance on this aspect of morality. Milton wants to ensure the freedom of thought without which knowledge becomes taboo to arrest the progress of civilisation. Unlike the so-called moralists, he accepts evil and holds that knowledge is the fusion of good and evil. To find out good one has to labour hard. Nothing can be rejected as useless or unnecessary without testing it. Knowing of evil does not mean acceptance of it. After proper enquiry, we can hold a thing immoral. The so-called moralists do not undertake the trouble of examining a thing before discarding and thus the morality they follow is nothing but a system that has stagnant and offers hindrance to the betterment of humanity. So, to be led by the knowledge of the past alone creates problems of hatred, pride, cruelty, injustice and immorality. Those people who do not allow others to think freely or bind others to their opinions without any room for self-understanding are the wicked race of deceivers. The exercise of conscience is an essential part of our acquisition of knowledge. Knowledge is neither moral nor amoral, it is neutral. To search into knowledge is the way to reach the correct use of knowledge. "We boast our light, but if we look not wisely on the sun itself, it smites us into darkness. Milton wants to "prove all things, and hold fast that which is good."

Morality cannot exist without freedom of thought and expression. In this regard, he saw all impositions upon the freedom of thought are illegal, undesirable and obstructions to the establishment of a right, honest moral society. For this reason, Milton demands liberty in thought and says, "Give me the liberty to know and to argue freely according to my conscience, above all liberties."