It is fair to say that all the natural sciences that man has accumulated through ages is derived from and based on empirical experience. That is to say, the raw data collected and received through our senses are internally processed by our mind and then a rational conclusion is drawn as a fact of life which makes our life easier. We touch a burning martial, we feel the pain on our hand and it registers in our mind as fact of life that we will avoid our entire life afterwards.
The component of rational processing appears to be more significant in some the branches of our knowledge such as humanities and art. In philosophy for example, being the most abstract subject to study, we still gather empirical data which often constitute part of the premises based on which we develop a rational argument to come to a conclusion.
The purpose of this post is to show that the nature of a "personal experience" is in truth not that different from other branches of human's knowledge and it is as credible, except for the fact that it does not lead to a quantifiable formula just in the same way that all disciplines of Arts and Humanities do not. To this end, I am going to contrast the nature of "empirical evidence", which leads to empirical science, with "Personal Experience" which results in faith in the context of a simple experiment of science.
Before that let's check their definitions in Wikipedia.
"Empirical evidence, also known as sense experience, is the knowledge or source of knowledge acquired by means of the senses, particularly by observation and experimentation."
"Personal experience of a human being is the moment-to-moment experience and sensory awareness of internal and external events or a sum of experiences forming an empirical unity such as a period of life."
The credibility of an empirical evidence mainly comes from two claims; firstly, it is said to be verifiable by everyone and secondly it is expected to bear the same results (absolute) in different experiments. We can evaluate these claims in an experiment to verify the effect of heat on the length of a piece of metal bar or a metal stick with a known length.
Simply, imagine we heat our metal piece for 10 minutes and then measure its length with a precise instrument suitable for the length we are measuring. The exact details don't really matter for our argument. We already know that it is going to be longer as a result of expansion by heat as a matter of basic scientific fact.
Scrutinizing this simple experiment, we ask;
1- Can anyone do this experiment with an accuracy that would meet the basic scientific standards? The answer is definitely no. You need to have some basic qualifications in order to be able to perform this experiment. Namely, you are required to know of how to work with the lab equipment and how to read the measuring devices.
2- Is the result, that is the length of the expansion of the metal piece, absolutely the same for different experiments by different people? The answer again is negative. They vary within a scientifically defined uncertainty limits. That is to say, the empirical evidence will show an expansion of length by 5 mm +/- 2% for every 1000 mm length of certain metal nature if heated up by 20 deg, for example.
3- Is the scientific conclusion of "heat increases the size of a metals" merely based on empirical data? Not really. There is a rational mental process involved which is done in our mind to conclude such a relationship between the heat and enlargement of a metallic object.
This leads us to believe that the main reason we accept an empirical experiment as a fact is essentially because of the general consensus of people having the same experience, which forms a general understanding of how a natural phenomena works and how we can manipulate it to our advantage with some anticipated uncertainty.
By the same reasoning, I would argue that if different people have similar "personal experiences" on the same subject, the consensus of their rationally processed conclusion is inevitably as credible as a scientific fact supported by "empirical evidence". By the way of example, if there are many people who claim that when they lie they feel bad and their consensus is lying has negative impact on satisfaction of life then this constitutes a fact of life derived from "personal experience".
Therefore, I would like to conclude that if there is a general consensus by a number of people who have come to a rational conclusion that certain events in their life lead them to believe in God who is running the world at every moment, this can be as credible as a scientific fact. Hence, it can not be dismissed as a source of human knowledge on the ground that it is derived from "personal experience" rather than "empirical experiment." .
As a matter of fact, faith in its essence is a rational conclusion (reasoning) in light of a collection of empirical data. We observe the world through our senses and the only hypothesis which make sense to us is that there has to be a creator. Therefore, the general consensus on this conclusion is the true sufficient condition for God to exist.
Needless to say, Everyone has the choice to deny all the scientific understandings of the world and to live a life of stone age style depriving themselves from the joys of a modern life. Likewise, it can be can be argued that ignoring the metaphysical nature of the world and the way things work may degrade the quality of our life substantially.
Last but not least, is to acknowledge the fact that the scientific grasp of the world, that is only applicable to nature, usually results in a law of a mathematical nature which helps us quantify the effect of the certain changes with respect to the natural status of things. This is while the in case of the metaphysical laws derived from "personal experience" we can not quantity their effect by some mathematical formula. For example, we can not say how much lie you have to say in order to feel so bad that you would feel so sick that you won't be able to go to work. The same is true about most of the disciplines of arts and humanities. Yet they are indispensable branches of human knowledge.
