I had told you last time similarity that was one example I gave you, when two things appear to be similar to each other. Now all similarities depend upon comparison, unless you compare one with the other, you cannot decide whether it is similar or not. Now comparison is done by what that is the question, by what means do you compare? According to Plato, you cannot compare by senses. Your senses can only perceive an object as it is but your senses cannot compare one with the other. Take for example how you compare sound and colour? Sound is judged by the ear and colour is judged by the eye. Now by what sense organ do you compare colour and sound? Sound only hears, eye only sees; by what sense do you compare? Is there any sense by which you can compare sight with hearing? It is something that is not sensed or there is a deeper sense in us. In Indian philosophy it is called the mind, not the sense, not the sense organs; it is the mind which compares. They say mind is the sixth sense. Senses are compared by an inner sense which is the mind which is not outer sense it is an inner sense. So according to Plato wherever there is comparison this comparison is not done by perception.
Now comparison is important for knowledge. You cannot have true knowledge without capacity to compare. So first is the comparison then knowledge of existence. I told you last time that you see normally objects which are existing but how do you perceive existence itself? For that you require to go beyond senses. It is by rational capacity that you perceive existence and third is the understanding of number. Now understanding of number is a very peculiar thing. You all have learnt arithmetic, geometry maybe algebra maybe you have studied mathematics itself, higher mathematics is in fact higher mathematics is science of numbers and the question is what is number? I don’t know if you have ever reflected the question what is number? We know 1,2,3,4,5,6 these are called numbers but how do you know what is two except that one object and second object are put together but on this object and this object nobody has written two. So by sensation you don’t get idea of two. It is because that these two objects are put together you call it two but supposing these objects were put separately then you would have not called them two. This is one object, this is another object both are one, one. When you put them together now you say its two but the word two is not written on anything; it’s not that you perceive two anywhere. What you perceive is this object and that object that’s all. If the same object was now put along with the third object you will now say it is three. The same thing is now called three. When it was only with this you call it two now you put a third thing and now the same thing you call now three. All three together is three. This was the theory of Pythagoras who came much before Plato. According to Pythagoras numbers are known not by senses but directly by the reason because reason understands what is three-ness, what is two-ness, what is four-ness, what is five-ness. So the knowledge of number, the knowledge of existence and comparison these three things are not learnt by senses. We may use senses to begin with but when you reflect upon them you find that they are not perceived by senses. Similarity I told you, comparison between colour and sound neither your ear makes a comparison nor your eye makes a comparison because eye can only see and ear can only hear but what is it that compares the sound and hearing; it must be something else other than the eye and the ear that which is something else is more than the senses similarly the knowledge of the existence. You see this object existing or that object existing but existence as such, what is existence as such? What is it to exist? This you conceive not perceive but you conceive. As I told you existence cannot be perceived it can be conceived, comparison cannot be perceived, comparison can only be conceived. Number cannot be seen, number is only conceived. These are three examples which Plato takes to show you that there is kind of a knowledge that by conception not by perception and he says perception is not knowledge it is conception which gives you knowledge.
We speak, for instance, of two things being unequal but this presupposes an ideal of equality which is not derived from perception, since there are no two things exactly equal to each other. This also is a very good example. We very often feel, you take two objects and measure them exactly equal and you feel that by seeing two equal things we have got the idea of equality but what you are seeing is one object and the other object. By what means are you comparing? How do you arrive at the idea of equality? It is something which is perceived, it is not perceivable it is conceived in the mind. We know, for instance, that color is different from sound, but there is no sense-organ which can perceive both. There must therefore be a faculty higher then sense-organs which is capable both of perceiving things directly without any aid or sense-organs as well as of making use of sense-organs. Moreover, an essential object of knowledge is existence, and this we do not perceive by sense-organs; it is the mind which directly reaches existence. Plato concludes that perception is not knowledge, because “it has not part in apprehending truth since it has none in apprehending existence.”
Senses do not give you knowledge because senses cannot give you the knowledge of existence and knowledge of existence is knowledge and not perception therefore he says that ‘perception is not knowledge’. Now we shall very read again this paragraph because it’s a very important paragraph. What is written in this paragraph can remain with you throughout your life because very briefly it gives you the whole basis of an idea of what is called Pure Reason. As I told you human beings are supposed to be rational beings, we are rational because we make use of reason and if anybody says what is reason then the best answer that you can give is this paragraph. So to be human being is to be rational, to be rational is to understand what is reason and to understand what is reason you should know the answer by reading this paragraph. So it is one of the most important things that we have been told by Plato, so we repeat. Particulars are, according to Plato, the objects of perceptions, and perception, he contends, is not knowledge. In his dialogue Thaetetus, he points out that comparison, knowledge of existence and understanding of number are essential to knowledge but they cannot be perceived by senses.
We speak, for instance, of two things being unequal but this presupposes an ideal of equality which is not derived from perception, since there are no two things exactly equal to each other. We know, for instance, that color is different from sound, but there is no sense-organ which can perceive both. There must therefore be a faculty higher then sense-organs which is capable both of perceiving things directly without any aid or sense-organs as well as of making use of sense-organs. Moreover, an essential object of knowledge is existence, and this we do not perceive by sense-organs; it is the mind which directly reaches existence. Plato concludes that perception is not knowledge, because “it has not part in apprehending truth since it has none in apprehending existence.”
This paragraph you may have to read again not only now maybe after five years, maybe after ten years; I have been reading year after year and very often it is a very good exercise of the mind to be reminded that when you try to understand what is Reason these examples are of direct use. So you’ll make use of these examples again and again and you will reflect upon them again and again. Now
That which the higher faculty perceives directly is, according to Plato, the essential and universal element in the particular.( When you see a particular as I told you yesterday, every particular has got in it universals. When you say this cat is black, you are seeing two universals – cattiness and blackness. Without apprehending these two universals you could not make a statement – this cat is black. You must understand what is cattiness then only you can say this cat. Unless you know what is cattiness you cannot say this cat and you cannot say this is black unless you know what is blackness. So whenever you see any particular every perception of particular involves a perception of universal. And to be very precise you should say every perception of a particular involves conception of universal. Universal is not perceived but is conceived. So whenever you see any particular, perception of the particular implies conception of universal.) This element he calls the Idea or the Form. Pertaining to each characteristic of a particular thing there is universal Idea by participating in which the particular thing is what it is. (According to Plato particulars are copies of universal. this cat or that cat is a copy of universal cat, universal idea of a cat.)