How do we know what we know? To know something, we must first of all establish what we accept as data, and what we consider requires definition and proof, that is, we must determine what we know already, and what we wish to know. And, we know from the very first step towards cognition that a man is struck by two obvious facts: The existence of the world in which he lives and the existence of consciousness in himself. Neither the one nor the other can he prove or disprove, but both of them are facts for him. This is all we have the right to accept as data. All the rest requires proof of its existence and definition on the basis of these two data we already possess. The direct outcome of these two fundamental data; the existence in us of a psychological life, i.e. sensations, representations, concepts, thinking, feeling, desires and so on, and the existence of the world outside us is a division of everything we know into subjective and objective, a division perfectly clear to our ordinary perception. Everything we take to be the properties of the world, we call objective, and everything we take as properties of our inner life, we call subjective. The 'subjective world' we perceive directly; it is within us. The 'objective world' we represent to ourselves as existing outside of us is most clearly denned by the fact that we perceive it as existing in time and in space and cannot perceive it or represent it to ourselves apart from these conditions. Usually, we say that the objective world consists of things and phenomena, i.e. of things and of changes in the state of things. A phenomenon exists for us in time, a thing exists in space. But such a division of the world into subjective and objective does not satisfy us. By means of reasoning we can establish that, actually, we only know our own sensations, representations and concepts, and that we perceive the objective world by projecting outside of ourselves the presumed causes of our sensations. Further, we find that our cognition of both the subjective and the objective world may be true or false, correct or incorrect. The criterion for determining the correctness or incorrectness of our cognition of the subjective world is the form of relationship of one sensation to others, and the force and character of the sensation itself. In other words, the correctness of one sensation is verified by comparing it with another of which we are more sure, or by the intensity and the taste of a given sensation. The criterion for determining the correctness or incorrectness of our cognition of the objective world is exactly the same. It seems to us that we define things and phenomena of the objective world by means of comparing them one with another; and we imagine that we discover the laws of their existence apart from ourselves and our cognition of them. But this is an illusion. We know nothing about things separately from ourselves and we have no means of verifying the correctness or incorrectness of our cognition of the objective world apart from sensations.
Since the remotest antiquity, the question of our relation to the true causes of our sensations has been the main subject of philosophical research. Men have always felt that they must find some solution of this question, some answer to it. These answers alternated between two poles, between a complete denial of the causes themselves, and the assertion that the causes of sensations lie in ourselves i.e. we have free will and not in anything external and the admission that we know these causes, that they are contained in the phenomena of the external world, that these very phenomena constitute the causes of sensations, and that the cause of observable phenomena themselves lies in some subtle forms of external world i.e. fatalism.
In simple words, free will is the ability to select a course of action as a means of fulfilling some desire which is under control of oneself. David Hume, put it as a power of acting or of not acting, according to the determination of one’s will while fatalism is the doctrine that all events are preordained and predestined in such a way that human beings do not have control over them. Nietzsche described it as an attitude of resignation in the face of some future event or events which are thought to be inevitable.
A huge debate is going on with lots of argument: both in favor and against. Natalie Barney sees fatalism as the lazy man's way of accepting the inevitable. Bill O'Reilly denied the concept of free will by saying “You don't have free will when you have lung cancer.” Alan Moore’s opinion is “As far as I can see, it's not important that we have free will, just as long as we have the illusion of free will to stop us going mad.” There are many who do not share either of these extreme views and hold a place midway between free will and fatalism. Kant established that our sensations must have causes in the external world, but that we are unable, and shall never be able, to perceive these causes by sensory means, i.e. by the means which serve us to perceive phenomena. Jawaharlal Nehru put it as “Life is like a game of cards. The hand you are dealt is determinism; the way you play it is free will.”
Life only thinks about itself. Life is only concerned about itself. Life everywhere faces two problems: survival and propagation. Life is being busy to resolve these fundamental issues or else goes extinct. In the words of Charles Darwin, “It is survival to the fittest.” Life in humans has some addition features due to having a larger brain in humans as compared to animals. The misery in humans hampers the quality and performance in terms of survival and propagation.
Thus, by determining everything we know is about survival and propagation through our senses in terms of space and time which is indeed confirmed by Special Theory of relativity that space and time are not properties of the world, but merely properties of our perception of the world by means of sense organs. In the words of Einstein, “Time and space are modes by which we think and not conditions in which we live.” Consequently, it is we who invest it with these properties when we sense and perceive it. Quantum Physics, further, acknowledges the role of an observer in the observed physical world. The observed physical world is described rather by a mathematical structure that can best be characterized as representing information and propensities: some information about all the possible choices is simultaneously present in the quantum state, and the possibility that any one of the mutually exclusive alternatives might be pertinent. Whichever choice the experimenter eventually makes, the associated set of predictions is assumed to hold.
According to Kant, everything we find in external world is put into it by ourselves. We do not know what the world is like independently of ourselves. Moreover, our conception of things has nothing in common with the things as they are in themselves, apart from them. And, most important of all, our ignorance of things in them is due not to our insufficient knowledge, but to the fact that we are totally unable to have a correct knowledge of the world by means of sense-perception which is in congruence with the Principle of Uncertainty. Heisenberg's Uncertainty Principle states that one cannot simultaneously know the position and momentum of an object with arbitrarily high precision. The more precisely the position is determined, the less precisely the momentum is known in this instant, and vice versa.
Sir Roger Penrose, studying the physical basis of consciousness applying quantum physics and Einstein's general theory of relativity on Plank's scale, figured out that consciousness involves a factor which is neither deterministic nor probabilistic but non-computable. Conscious choices and understanding may be non-computable and life may be seen as a combination of deterministic pre-conscious processes acted on by a non-computable influence.
It could be deduced that one can never know whether free will or fatalism. It is also clear that the main question is not about the free will or fatalism but to avoid the misery or sorrow in life. All schools of philosophy and religions are directed to solve this problem. The theory of free will, fatalism or concoction of both was devised to tackle this problem. It is now a well establish fact that relaxation in concepts of absolute free will and fatalism appeals most of the people and could better cope with misery in majority. When Yagyavalkya, ancient Upanisada sage of India, was asked about free will or fatalism, he said “The concept of free will and fatalism are like two wheels of a cart; if anyone is missing, the cart only moves in circle- round and round. To ensure proper movement on path, one needs to use both the wheels.”
The same confusion was put before Muhammad and he asked the person to lift one of his legs. The person lifted his left leg. Again, the Prophet asked the person to lift another leg but he is bound and could not lift his leg. Initially, the person was free to lift his leg; in fact, he had options to choose whether he wanted to lift his left leg or right leg. As soon as he chose, he became bound. The concoction of free will and fatalism could also be understood by considering a sailboat analogy. A sailor sets the sail in a certain way; the direction the boat sails is determined by the action of the wind on the sail. One cannot change the direction of the wind but can adjust the sail to be in right direction.
One could think beyond space and time but could only express within the limits of space and time. Conscious choices may be non-computable but expressed algorithmically through deterministic or probabilistic statements. It could better be understood through biology of brain. The newest area of human brain is neocorex. The neocortex is responsible for rational and analytical thought and language. The limbic brain is responsible for all of feelings, such as trust and loyalty. It is also responsible for all human behavior and all decision-making, but it has no capacity for language. The communication takes place directly with the part of the brain that controls decision making, and the language part of the brain allows rationalizing those decisions. The part of the brain that controls the feelings has no capacity for language. It is this disconnection that makes putting feelings into words so hard. Again, the part of the brain that controls decision-making doesn't control language, so we rationalize. Rationally, one knows that one’s explanation isn't the real reason. So, enlightened people could not express the higher level of consciousness in words and keep silence over the subject and when speaks one’s version is found to be different from another enlightened one’s rationally as in the case of Muhammad’s explanation and sailboat analogy.
There are also the cases where absolute free will was experienced; that is why, statements such as “Thou art That” and “I and My Father are One” were stated independently in different cultures and religion. It is not possible to obtain absolute free will without entering in the realm of occultism and very few would have such psychology-type to combat misery in one’s life.
Basically, human beings can be broadly classified into four types according to their psycho-somatic conditions: the active type, the mystic type, the philosophic type and devotional type. This classification is based on the predominance of one or the other three aspects of the human mind: the will, the intellect and emotions. In the light of latest biological researches, the active type, devotional type, the philosophic type and the mystic type can be attributed to neurological pathway dominated by four major neurotransmitters: testosterone, estrogen, serotonin and dopamine respectively.
Any single theory or concept could not meet the different requirements of all pyscho-somatic types. So, it is obvious to formulate various theories and concepts to alleviate sorrow and misery in one's life keeping in mind the necessities of different psycho-somatic types.
You have your way. I have my way. As for the right way, the correct way and the only way, it doesn't exist.