Descartes and Plato are two of the most influential thinkers within philosophy. The allegory of the cave and systematic doubt are also two of the most famous concepts within philosophy. Plato at the time of writing the cave allegory was trying to resist the growing influence of the Sophist philosophers who prioritised semantics and rhetoric over truth.1 Descartes by introducing radical scepticism to philosophy was challenging traditional scholastic philosophy which had dominated the philosophy for many centuries. While both pieces of writing are separated by different ages of time and space, they share many similarities as well as fundamental differences. This essay will attempt to compare and contrast these two bodies of work by firstly explaining what is Descartes’ systematic doubt and Plato’s Allegory of the cave before finally examining the similarities and differences between them in the final paragraph of analysis. Descartes in his first meditation introduces the concept of Radical doubt which similarly places suspicion on the senses and the appearance of things. This involves stripping away all one’s beliefs and preconceived notions in order to find the foundational bedrock of knowledge in which all sciences could then grow.
Descartes begins his first meditation by casting doubt on all his beliefs, if a belief can be even slightly doubted it must be discarded. He wants to ‘reject as absolutely false anything in which I could imagine the least amount of doubt3’ this is called radical scepticism where all beliefs must be challenged. Through this experiment Descartes conceded that the physical senses are not to be trusted as they have deceived him before, this is known as sensory deception and this revelation forces him to doubt any beliefs about the external world and knowledge that is gathered by the five senses. His examination also reveals that dreams states can be difficult to distinguish between waking life, this has happened before where he thought he was in bed but wasn’t. Henceforth one cannot truly know if they are awake observing reality or asleep enjoying a dream, this is known as the dream hypothesis. Descartes also uncovers the evil demon hypothesis whereby all external reality observed may be just an illusion that is perpetrated by an evil demon seeking to deceive him, also there is the problem that all previous memories about oneself could simply just be imagination and not grounded in any reality.
The system of radical doubt leads Descartes into murky territory where he cannot believe in the existence of anything at all. This thankfully is changed when he discovers the cogito’ I think therefore I am’, his starting point which saves him from uncertainty, allowing him to prove that he exists. In Plato’s allegory of the cave, there are prisoners who are locked up within the depths of a cave. All day long, they are situated in front of a wall and behind them is a fire which reflects shadows on the wall. Unbeknownst to the prisoners, there are puppeteers who use the firelight to reflect shadows of their puppets upon the wall while making noises ‘the truth would be literally nothing but the shadows’. The prisoners are unaware of this illusion and mistakenly believe these shadows are real images. One day, a prisoner is released from his chains and allowed to walk freely about the cave. Although it is confusing for him to see the puppets and fire, he is forced to accept this clearer version of reality and eventually ascents through the cave, spending a day and night under the sun and the stars. As he becomes familiar with the world above, he realises the sun is the giver of light, how it casts shadows and how his prior life in the cave was an entire illusion.
This newfound enlightenment Plato remarks will prevent him from ever returning to the life in cave, nor will his old inmates believe him if he tried to free him, instead ‘they would put him to death5’ This intellectual awakening will cause the inmate to grasp the idea of good, the eternal form which will urge him to act ‘rationally in public or private life6’. Ultimately Plato suggests the inmate should return to his old friends and seek to help them. The cave analogy is concerned with the human condition and its’ lack of enlightenment, for Plato the prisoners represent ordinary citizens who hold false beliefs (shadows), reality is dictated to them by their senses (appearance of things) allowing them to be easily manipulated. Ignorance is then symbolised by darkness and the intellect and reason is symbolised by the light. The journey of the inmate from darkness to light is a metaphor for education which allows one to progress from the ignorance in the depths of the cave to the intellectual plains of the enlightened one in the outside world.
The outer world symbolises true knowledge, the realisation of eternal forms while the cave again illustrates the world of appearance and false beliefs, Woozley writes ‘most men without knowing it live in this shadow world’9 The cave analogy and Descartes systematic doubt have much in common. Both are concerned with the illusory nature of the senses and external reality, for Plato people place too much emphasis on the senses, on the appearance of things as illustrated in by the shadows on the wall, this leads them to hold false beliefs and to be easily misled, only by entering the realm of thought can people free themselves by gaining knowledge and becoming enlightened. Descartes through the systematic doubt also maintains that external reality cannot be truly known; the sensory deception and evil demon hypothesis cast doubt on the authenticity of the outside world. Indeed the evil demon hypothesis is an almost identical scenario to that of the prisoners whose sensory perception is distorted by the shadow wielding puppeteers. Only through the mind or intellect can an individual overcome the illusory nature of the senses, it allows the prisoner to access the outside world to gain enlightenment and help his fellow inmates while for Descartes the mind by way of the cogito is the one thing that cannot be doubted which through it allows him prove the existence of the outside world in his later meditations.
The cave is an analogy which illustrates how people can possess false consciousness and how through reason and knowledge one can overcome this while systematic doubt is an instruction on how to discard false beliefs, the ascent through the cave into the intellectual world is the finishing point for Plato while the cogito for Descartes is a starting point for further investigation. The two authors also differ on the type of philosophy employed in their argument. Plato insists that after the ascent , the prisoner will experience the idea of the good ‘ the lord of light in the visible world, and the immediate source of reason and truth in the intellectual’10 the good then is the highest point of knowledge and represents Plato’s philosophy of perfect types or forms known as idealism, Descartes through highlighting the sensory, dream and demon hypothesis illustrates how the external world cannot be relied upon as a basis for true knowledge, but the cogito is a starting point, the attempt to find secure beliefs that allow a foundation for further knowledge to be rested upon is known as Foundationalism which is credited to Descartes.
In conclusion, both Descartes and Plato in their attempts to challenge the prevailing doctrine of their respective times introduced two of the most influential concepts in the world of Philosophy. Descartes through his examination of systematic doubt uncovers the limitations of the physical senses in acquiring knowledge and introduces further challenges to understanding external reality with the dream, memory and evil demon hypothesis. Only through the mind alone can one grasp the nature of reality starting with the cogito. Likewise Plato is concerned with the appearance of things, how the senses can deceive us and humanity like the inmates in the cave can live in a state of ignorance or darkness if they don’t use the power of the mind to acquire knowledge and reason. Only through using the intellect can humanity gather true knowledge and escape the darkness in the cave. For both the intellect is the only means for gathering true knowledge, the senses are illusory. Descartes systematic doubt and cogito provide the foundational starting point for the sciences while the cave allegory offers advocates a way of life for humanity to feign the world of ignorance and seek true knowledge so that those who acquire it will return to the cave and help their fellow man.
Annas, Julias. An Introduction to Plato’s’ Republic. New York: Oxford University Press Cottingham, John. Descartes: Meditations on First Philosophy. New York: Cambridge University Press, 2013 Cottingham, John. Ed. Ray Monk. Descartes’ Philosophy of Mind. London: Phoenix Publishers, 1997 Plato. The Allegory of the cave. Week 5 Handout
Woozley, Anthony. Plato’s Republic: A philosophical commentary. London: MacMillan Publishers, 1989