The analogy of the Divided Line comes at the end of the Sixth Book of Plato's the Republic (Rep 6. 509 d- 6. 511e). This analogy seeks to describe human knowledge by using a line separated to form various segments. Plato from the onset makes two distinctions, that is, the physical things on one end of the spectrum and on the other end the non-physical (things known via intellect). This subject matter is then divided into four levels. These are: Eikasia (imagination, conjecture, picture thinking) ; Pistis (Faith or conviction, practical, real-world knowledge) ; Dianoia (Understanding, scientific, mathematical, logical knowledge and Noesis (Reason, direct apprehension, wisdom). Eikasia is the first segment in the spectrum of the visible and comprises of images. Eikasia is indeed the imagination that results in images say shadows and reflections. Shadows and reflections are produced by solid bodies (Uebersax, 2006).
Plato describes the second segment in the spectrum of the visible as just but a resemblance of Eikasia. Various phenomena are the objects from which faith or belief are drawn with belief being the belief in objects that produce shadows and reflections. These objects include animals and plants and objects that can be manufactured. Apprehension is based on the 5 body senses; man's bodily perceptions. Dianoia is the lower segment of the intellectual spectrum. Here Plato underlines the power of critical and logical interpretations. Reasoning is only to begin from given standpoints or premises. Enquiries are only to be undertaken via hypotheses. Conclusions are to be reached only after hypotheses are investigated. For example in geometry the odd, the even, figures, the 3 kinds of angles are the assumptions on which students draw their conclusions. These are hypotheses; they guide the students into reaching logical conclusions (Uebersax, 2006).
Noesis is the higher division of intellect. According to Plato, the human soul does not place emphasis on hypotheses but looks up to principles that go beyond premises or hypotheses. Unlike Dianoia, Noesis does not take into account images but knowledge is advanced upon via ideas as they exist at that point in time. Reason is to be attained via dialecticism without the help of obects. Hypotheses are not first principles in themseslves. They remain just hypotheses; steps and points of departure that in the end lead us into a world beyond the confines of premises. Noesis is thus a higher science which though hinged on abstractions and devoid of illustrations (images), is defined by tests on the validity of hypotheses. Knowledge is based on a proposition accepted by all. A universal truth of sorts.
In conclusion it can be said that the segment on dianoia comes out as superior to the other segments on account of its high level of clarity. One bases concepts on objects. We could say that there exist relations among the various segments of Plato's Divided Line albeit with an intended strictness. The cornerstone of the Divided Line is that ideas are to concepts as objects are to images. It is absurd to attempt to directly draw relations between objects and concepts. It is only via images or objects that relations can be drawn. A kind of equality exists in the Divided Line. It is this equality that makes Plato's Divided Line vital to understanding the visible spectrum and the non-visible. Predication of knowledge is to be undertaken based on content; objects that evoke sensations in us or via hypotheses that define relationships, hypotheses that offer the chance for justifications to be made by way of intellectual intuitiveness (noesis) or by recollection of events and facts.
Work Cited:
Uebersax, John "Plato's Divided Line Analogy". Web. 2006. Retrieved from http://john-uebersax.com/plato/plato1.htm on 21/06/2012
