The Age of Reason - René Descartes (Leaving Cert Religious Education): Revision Notes
The Age of Reason - René Descartes
Introduction to the Age of Reason
The Age of Reason, also known as the Enlightenment, was a transformative period during the 17th and 18th centuries in Europe. This era witnessed remarkable scientific progress that fundamentally challenged traditional ways of understanding the world and established religious beliefs.
During this time, the Church initially resisted these new intellectual developments. Religious authorities felt threatened by scientific discoveries that contradicted established doctrine. A famous example was the Church's condemnation of Galileo for supporting the heliocentric theory - the idea that Earth orbits around the Sun.
René Descartes (1596-1650)
Background and approach
René Descartes was a French philosopher who became one of the most influential thinkers of the Age of Reason. Like the ancient Greek philosopher Socrates, Descartes believed that asking questions was the key to discovering truth. However, Descartes took this approach to an extreme level by questioning absolutely everything, including his own existence.
The method of systematic doubt
Descartes developed a philosophical approach called "hyperbolic doubt" - a method of reasoning where he deliberately doubted everything that could possibly be doubted. His goal was to find at least one thing that could not be questioned, which would serve as a foundation for all other knowledge.
Descartes argued that true seekers of truth must be willing to doubt everything at least once in their lives. Through this process, he discovered something remarkable: even while doubting everything else, he could not doubt that he was thinking.
This led to his famous conclusion: "I think, therefore I am." Since he was capable of thought, he must exist as a thinking being.
Distrust of the senses
As both a philosopher and scientist, Descartes sought knowledge that was absolutely certain and beyond doubt. He believed that anything questionable should be rejected, including traditional religious teachings and sensory experience.
Descartes argued that our senses are unreliable sources of knowledge because:
- Distance can distort what we see
- Our senses can deceive us (things may not be as they appear)
- We might be dreaming and not know it
- An "evil genius" - a powerful deceiving entity - might be manipulating our perceptions
The wax argument
To demonstrate the limitations of sensory knowledge, Descartes presented his famous wax argument, which illustrates how our understanding goes beyond what our senses tell us.
Worked Example: Descartes' Wax Argument
Step 1: Observe the wax's sensory characteristics A piece of wax has specific characteristics: particular shape, texture, size, colour, and smell.
Step 2: Apply heat to change the wax When the wax is brought near a flame, all these sensory characteristics change completely.
Step 3: Recognise the philosophical insight Despite this transformation, we still recognise it as the same piece of wax. This shows we cannot rely on our senses to understand the true nature of the wax.
Conclusion: We must use our mind and judgement, not our senses, to understand reality.
As Descartes stated: "What I thought I had seen with my eyes, I actually grasped solely with the faculty of judgement, which is in my mind."
Mind-body dualism
Through his scientific reasoning, Descartes concluded that reality consists of two separate substances:
- Mind (thinking substance) - responsible for thought and consciousness
- Body (physical substance) - the material, mechanical aspect of existence
After establishing his own existence as a thinking being, Descartes spent considerable effort trying to prove how the mind and body interact. He theorised that the body operates like a machine connected to the mind through a small gland in the brain.
Later life and persecution
Eventually, Descartes moved from France to Holland to escape religious persecution. The Church was actively persecuting scientists like Galileo, and Descartes wanted the freedom to continue his intellectual work without interference.
Later in his life, he was invited to Sweden to teach Queen Christina. Unfortunately, he contracted pneumonia while there and died in 1650.
Key Points to Remember:
- The Age of Reason challenged traditional religious beliefs through scientific advancement and rational thinking
- Descartes used systematic doubt to find certain knowledge, concluding "I think, therefore I am"
- The wax argument demonstrates that our senses can deceive us and that true knowledge comes from the mind, not sensory experience
- Descartes believed reality consists of two separate substances: mind (thinking) and body (physical)
- His work laid important foundations for modern philosophy and scientific method, despite facing Church opposition