Reasoning and Descartes

In the 17th century reasoning is the instrument of knowledge that compels man to question and analyse accepted ideas. In fact, still shaken by the humanist revelations of the Renaissance, society in the 17th century is in quest of truth. Recent scientific discoveries drive it to question the origin of man and of the world in greater depth. God's existence is no longer sufficient to justify the incomprehensible, and a philosophical approach spreads progressively to influence scientists in their reflection and research.
Science tries to make itself heard, even though the Church often blocks its path, notably in Italy where Galileo is forced to renounce his interpretations on the planetary nature of the earth. But this thirst for truth also implies a questioning of the methods used to attain it.
Theories and philosophical proceedings abound, with distinct and opposing schools of thought. For the libertines, man must understand the laws of nature and apply reason as a consequence, without calling on God and without being too concerned with the complexities of the world. For the believers, reasoning starts with God, but draws on differing principles depending on whether the believer is Protestant, Jansenist or Jesuit. It is with Descartes that the quest for truth really takes on a new dimension. Without denying God, he develops a rigorous method that puts reason, and therefore reasoning, at the centre of the debate to bring man towards knowledge.
In tune with his country's rejection of the baroque movement, Descartes proposes the classic trend of the 17th century, an approach in which rigor and consistency are the foundation of society. In his Discours de la méthode, he lays down the rules that constitute a guide for the acquisition of knowledge. Reason, analysis, synthesis and verification are the essential bases of his method, bases that from then on define a French spirit soon known as “ Cartesian ”, such is its influence in France on the manner of thinking and especially on reasoning.