Misleading Notions of the Sophists and the Skeptics
Source: Al-Mizan by Allamah Tabatabai
Man in his early childhood perceives the objects around him; he knows them without knowing that he knows, that is, without being aware that he has, or is using, a faculty called knowledge or cognition. This continues until a time comes when he finds himself doubting or presuming a thing. Then he realizes that before that he was using "knowledge" in his life affairs. He also gradually comes to understand that his perception or concepts are sometimes wrong, that error cannot be in the materials that he perceives - because those material things are facts and facts cannot be non-facts, that is, cannot be wrong. Therefore, the error must be in his perception. When there is no error in perception, it is knowledge - a perception that leaves no room for opposite ideas.
By these stages, he becomes aware of the basic principle that positive and negative are mutually exclusive and totally exhaustive; they are contradictories, they cannot both be present nor can both be absent. This fundamental truth is the foundation-stone of every self-evident or theoretical proposition. (Even if one doubts this statement, he intuitively knows that this "doubt" cannot be present with its negative, with its "no doubt".)
Man relies on knowledge in every academic theory and practical function. Even when he feels doubtful about a matter, he identifies that doubt by knowing that it is a doubt. The same applies when he does not know, or only presumes, or merely imagines a thing, he identifies it by the knowledge that it is ignorance, presumption or imagination.
But in ancient Greece, there arose a group, the Sophists, who denied existence of knowledge. They showed doubt in every thing, even in their own selves, even in that doubt. The Skeptics of later days are almost their successors. They deny knowledge of every thing outside their own selves and their own minds. Their "arguments" run as follows:
First: The most potent knowledge (that comes through the five senses) is often wrong and in error. Then how can one be sure of the knowledge obtained through other sources? How can we rely, in this background, on any knowledge or proposition outside our own selves?
Second: When we wish to comprehend any outside object, what we get is merely its knowledge; we do not grasp the object itself. Then, how can it be possible to grasp any object?
Reply to the First Argument:
First: This argument negates and annihilates itself. If no proposition can be relied upon, how can one rely on the propositions and premises used in this argument?
Second: To say that a source of knowledge is "often" wrong, is to admit that it is also correct many times. Then how can it be rejected totally?
Third: We have never said that our knowledge is always correct. The Sophists and the Skeptics affirm that no knowledge is correct. To refute this universal negative proposition, a particular affirmative proposition is sufficient. That is, we have only to prove that some knowledge is correct; and we have done so in the second reply.
Reply to the Second Argument: The issue in dispute is knowledge, which means to unveil an object. The Skeptics admit that when they try to comprehend an object, they get its knowledge. Their only complaint is that they do not grasp the object itself. But nobody has ever claimed that knowledge means grasping the object itself; our only claim is that knowledge unveils some of the realities of its object, that is, of the thing so known.
Moreover, the Skeptic refutes his own views practically in every movement and at every moment. He claims that he does not know anything outside his own self, outside his own mind. But when he is hungry or thirsty, he moves to the food or water; when he sees a wall falling down, he runs away from it. But he does not try to get food when he just thinks about hunger, and does not run away when he just thinks about a falling wall. It means that he does not act on the pictures in his mind - which he claims are the real things, and acts on that feeling or perception which comes to him from outside - which, according to him, does not have any reality and should not be relied upon!
There is another objection against existence of knowledge. They deny existence of established knowledge; and have laid the foundation of today's natural sciences on this rejection. Their reasoning is as follows:
Every single atom in this world is in constant movement; every single thing is continuously moving towards perfection or deterioration. In other words, what a thing was at a given instant, is not the same in the next. Understanding and perception is a function of brain. Therefore, it is a material property of a material compound. Naturally, this process too is governed by the laws of change and development. It means that all functions of brain, including knowledge, are constantly changing and developing. It is, therefore, wrong to say that there is any such thing as established knowledge. Whatever knowledge there is has only relative permanence - some propositions last longer than others. And it is this impermanent conception that is called knowledge.
Reply: This argument is based on the presumption that knowledge is not non-material and abstract; that it is a physical thing. But this supposition is neither self-evident nor proved. Knowledge is certainly non-material and abstract. It is not a physical and material thing, because the attributes and properties of matter are not found in it:
1. All material things are divisible; knowledge, per se, is not divisible.
2. Material things depend on space and time; knowledge, per se, is independent of space and time. An event happens in a certain place and time, but we may comprehend it in any place and at any time without any adverse effect on its comprehension.
3. Material things are admittedly governed by the law of general movement and constant change. But knowledge, per se, does not change. Knowledge, as knowledge, is incompatible with change, as one may understand after a little meditation.
4. Suppose that knowledge, per se, is subject to constant change like matter and material things. Then one thing or event could not be comprehended with the same details, in exactly the same way, at two different times. Nor could a past event be remembered correctly later on. Because, as the materialists have said, "what a (material) thing was at a given instant is not the same in the next".
These comparisons show that knowledge, as knowledge, is not a material or physical thing. It must be told here that we are not talking about the physical actions and reactions which an organ of a sense or the brain has to undergo in the process of acquiring knowledge. That action and reaction is a process, or a tool, of knowledge, it is not the knowledge itself.
For more detailed discussion of this subject one should study the philosophical works.