Essay – Plato’s Theory of Knowledge

October 16, 2018
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To what extent is Plato’s theory of the Forms a convincing theory of knowledge?

“To what extent” is one of the trigger phrases used by the examiner, and to answer questions convincingly requires nuance (meaning that you need to explain clearly whether the whole fo Plato’s theory falls down for various reasons, or just part of it, and if so, which part. You also need to unpack the word ‘convincing’ – in what sense and to whom?). Here is an example essay written by an experienced to teacher to demonstrate practically how this might be achieved. PB

Plato’s rationalism marks him out from other ancient thinkers such as Heraclitus in his rejection of the ever-changing physical world as a source of knowledge.  Instead, he proposed that knowledge is to be found in a transcendent realm of the Forms. The Forms, however, do not provide a convincing theory of knowledge. Instead, Aristotle’s account of knowledge gained through experience is more convincing and supported by the philosophy of Locke in the 17th century and later A.J Ayer in the 20th century. While Ayer’s verificationism raises the problem of relativism, I shall argue that these problems must be solved by an empiricist approach, rather than Plato’s mysterious realm of the Forms.

Heraclitus observed that ‘No man can step in the same river twice’, which acknowledged that the physical world is constantly changing. Plato insists, however, that there exists an eternal, perfect and immaterial form of physical objects; the properties of physical objects and values, such as justice, beauty and truth. This can be seen as part of a convincing theory of knowledge to the extent that it explains how a person can recognise particular things as belonging to a universal idea, even if those particular things are imperfect reflections of their universal form; for example, one can recognise different dogs as dogs because they have an innate memory of the form of a dog, according to Plato. This innate memory, Plato explains, comes from before birth when the soul belonged in the realm of the forms.

The problem with this theory of knowledge, however, is that there is no evidence that there actually exists a realm of the forms. John Locke was an empiricist who argued that we gain knowledge from experience. We understand the concept of a dog not because we recollect the Form of a dog that exists independently of any particular dog, but because we are able to compare a particular dog to other dogs that we have experienced. Using our imagination, we can then abstract the concept of a dog from those experiences of the things that all dogs have in common. Aristotle, also an empiricist, argued that ‘goodness’, rather than existing in a mysterious realm of the forms as the source of all perfection and existence, is only meaningful as a judgment about whether or not something fulfils its function in practice, e.g. a knife is ‘good’ if it cuts well.

One may argue that not all knowledge is based on experience, for example, the idea of a unicorn. Some knowledge, therefore must be innate in a way similar to how Plato describes. John Locke, however, in his ‘Essay concerning Human Understanding’, argues that even ideas in our imagination are based on a combination of things drawn from experience. He suggests that if certain ideas were innate, like the law of non-contradiction, then ‘children and idiots’ would understand them, but there is no evidence that they do.

Iris Murdoch, in the 20th century, argued that Plato’s theory of knowledge is convincing. She argued that there must exist a Platonic form of ‘goodness’ that guides us to become better people and rise to an external standard of morality. This may be convincing if we consider that without this, when we judge something as good or beautiful, we are just expressing an opinion based on popular opinion. This would mean that values are relative and we would be unable to judge others for acts or views that we intuitively perceive as absolutely wrong, e.g. rape or genocide. Plato was warning against relativism in his allegory of the cave when he describes those who are bound by popular opinion as being prisoners who merely see shadows on a wall as oppose to the real objects of knowledge, the forms. Plato further explains this idea with the analogy of the divided line that shows that the forms are more real than physical objects by a ratio of 2:1, an idea that was influenced by Pythagoras.

Ayer, however, would argue that Plato’s theory of knowledge is unconvincing because the Forms cannot be verified. He denied the existence of any ‘“reality transcending the limits of all possible sense-experience”’ and argued that any statement that cannot be directly or indirectly verified is meaningless. This implies that statements about goodness and beauty (both of which Plato believes to be Forms of absolute truth) are relative and simply expressions of emotion. Ayer’s approach to knowledge is more convincing than Plato’s because it is based on what can be scientifically proven, however, the problems of relativism that have just been raised are unavoidable on Ayer’s understanding of knowledge.

Aristotle and Locke’s common sense empiricism more convincingly explains how we have knowledge of concepts derived from physical things. While there may be problems with relativism on Ayer’s understanding of concepts like goodness and beauty, Plato’s Forms are unverifiable. There must be a solution to the problems of relativism that are based on a scientific, verifiable view of the world.

Clare Handzel, Head of Religious Studies, St John’s School, Leatherhead



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