The Closing of the Western Mind: The Rise of Faith and the Fall of Reason by Charles Freeman Page B

to his listeners—whether he himself recognizes it or not, his art lies primarily in deception. For him, Isocrates’ claim that it was simply a matter of training speakers to be more morally upright failed to reach the heart of the problem; instead what was needed were objective standards by which to judge moral concepts such as “good,” “evil” and “justice.” Establishing these standards was the task that Plato set himself. 7
    One of the major influences on Plato was Pythagoras. Pythagoras, active at the end of the sixth century B.C., had been dead for a hundred years, but his followers in southern Italy had preserved his teachings, and Plato visited them in 388 B.C. Among these teachings was a belief that numbers underpinned the natural world. Pythagoras had used the example of a string stretched across a sounding box. Pluck it and record the note. Halve the length of the string and pluck it again, the note is precisely one octave higher. So unseen numbers appear to be present at a different and, Plato argued, more significant level than the world appreciated by the senses. Plato developed this idea to suggest that not only numbers but values and even objects existed beyond this world and at a more perfect level of reality. So while a picture may be beautiful, its beauty, which is essentially transient, is only a reflection and a part of a much greater eternal beauty. This Form of Beauty, as Plato called it, comprised all the elements of beauty known on earth but was in itself greater than they were. It was far more valuable to come to know this Form of Beauty than to search without success for transient beauty in the natural world. There could be Forms of many different entities—in his so-called Seventh Letter Plato suggests there might be Forms “of shapes and surfaces, of the good, the beautiful and the just, of all bodies natural and artificial, of fire and water and the like, of every animal, of every quality of character, of all actions and passivities.” 8 Furthermore, Plato suggested that the Forms were not all equal, existing alongside each other, but that they could be arranged hierarchically. If the Forms of “Justice” and “Beauty” are “good” in themselves, then they must form part of a superior Form of “the Good,” which could be compared to a sun among other lesser sources of light.
    The world of Forms could be grasped by the human soul, which Plato believed was immortal and passed from one body to another on death. Plato was fascinated and perplexed, as many Greek philosophers were, by the relationship between reason and emotion. His solution was to see the soul as split into three parts: a reasoning part, another sensual part based on “desire” (hunger, thirst, sex) and a third on “spirit,” which encapsulated emotions such as anger and the desire for honour and reputation. To Plato the reasoning part was by the far the most important; he argued that maturity, in effect the ability to act virtuously, came from bringing the “desiring” and “spirited” parts of the soul under the control of reason. 9 The reasoning part of the soul could achieve its own maturity by grasping the nature of the Forms, which, Plato claimed, it had actually always known but had forgotten. He makes the point in his dialogue the
Meno.
Meno is a slave who is led through a mathematical proof that deals with the area of a square (which quadruples when the length of its side is doubled). Plato argues that the knowledge that the proof was true was concealed in Meno’s soul and simply had to be “recollected.” The proof relating to the area of a square could be said to exist as a truth which would be true in any circumstances at any time. In other words, it exists independently of the material world and continues to exist even if no human soul is aware of it.
    A mathematical proof such as that presented to Meno can be proved by and to any whose minds are capable of elementary deductive logic. But