Common to all Enlightenment philosophers was that they appreciated reason, religious tolerance, and natural rights: life, freedom and property.
1. One of them was Jean-Jacques Rousseau (28 June 1712 - 2 July 1778), a Geneva philosopher, writer and composer. His political philosophy influenced the spread of the Enlightenment in Europe, as well as the aspect of the French Revolution, the development of political and educational thought. His idea was, as with some other thinkers of that time, that the hypothetical State of Nature was a normative guide. He considered that the "uncorrupted morale" of a man lies in his natural state and that there is a naturally occurring temperance in humans, despite the fact that they live in a rash a corrupted climate of civilization. The influence of civilization is reflected in the fact that man's nature has undergone some changes, and has become obvious characteristics of indolence and hatefulness due to the developed ego. He claimed that the stage of human development is related to the stage of "savage" that is optimal during development, between the less optimal extreme animal , on the one hand, and extreme decadence of the civilization on the other.
"The first man who, having fenced in a piece of land, said 'This is mine', and found people naïve enough to believe him, that man was the true founder of civil society. From how many crimes, wars, and murders, from how many horrors and misfortunes might not any one have saved mankind, by pulling up the stakes, or filling up the ditch, and crying to his fellows: Beware of listening to this impostor; you are undone if you once forget that the fruits of the earth belong to us all, and the earth itself to nobody".
Unlike traditional beliefs, especially medieval, man, with his natural laws and rights, in the teachings of this philosopher, as well as others, gets a more important place, human beings are at the center of interest, not some imposed dogma.
2. Adam Smith (16 June 1723- 17 July 1790), was a Scottish philosopher, economist and author, was regarded as a pioneer of political economy and a key figure of the Scottish Enlightenment. He set the foundations of the classical free market economy. The "Wealt Of Nations" is the forerunner of the modern academic discipline of economics. In this and other works he developed the concept of division of labor and explained how rational personal interest can lead to general national prosperity. He criticized the thinking of his time, and pointed out that conscience emerged from dynamic and interactive social relations, through which people sought "mutual sympathy of feeling".
“Wherever there is great property there is great inequality. For one very rich man there must be at least five hundred poor, and the affluence of the few supposes the indigence of the many. The affluence of the rich excites the indignation of the poor, who are often both driven by want, and prompted by envy, to invade his possessions.”
What s certainly different in his teachings from the previous ones, the attitude towards the economy as a national interest, is equally the right of everyone to participate in personal economic development and development in general, and not just privileged individuals and classes.
3. Denis Diderot (5 October 1713 – 31 July 1784) was a French philosopher, art critic, and writer, known as co-founder, chief ditor and associate of the Encyclopedia. He considered work in the church priesthood, and briefly dealt with the law, and then decided to become a writer. His Enlightenment thought was directed at materialism and atheism. As an opponent of occultism and mysticism, which were widespread in France, he claimed that religious truths and claims must be subjected and explained by reason, mystical experience or esoteric secrets. Yet he showed interest in the work of the alchemist Paracelsus. As his contemporaries claimed Diderot was a philosopher in which all the contradictions of the times were struggling with one another. He also dealt with scientific work, primarily in areas of acoustics, tension, air resistance.
"Fanaticism is just one step away from barbarism".
"A thing is not proved just because no one has ever questioned it. What has never been gone into impartially has never been properly gone into. Hence scepticism is the first step toward truth. It must be applied generally, because it is the touchstone".
His work is clearly opposed to the teachings of the Church, because of the omission of reason in these teachings and excessive mysticism. Everything that is in nature as the source and purpose of man's existence should be subjected to reason.
The Church generally showed the fear of all the Enlightenment philosophers and their teachings, for the rejection of dogmas, the increase of the natural rights of people, the release of medieval stigma, the examination of all religious claims by common sense, the emergence of a free market.