Scientific Philosophy and Principles in Medicine

By Zekâi Şen

Scientific Philosophy and Principles in Medicine is an accessible treatise on the philosophy that guides medical practice. It lays the foundation of a multidisciplinary framework behind the development of the medical profession. The book presents 10 chapters that cover issues that are frequently encountered by medical professionals in their career: philosophical and linguistic principles of rational thought, scientific, crisp and fuzzy logic, diagnostic aspects, the history of medicine, epistemological concepts, approximate reasoning, principles of medical wisdom, numerical and graphical diagnostics, and the collaboration of researchers involved in the fields of engineering and medicine.

The author of the book brings several years of teaching experience and medical practice into this reference with the goal of integrating principles of scientific philosophy and logic into medical education. Readers will understand the process of devising rational diagnostic and treatment approaches that support human health as a generative process that seeks to solve problems through creativity, rather than a classical process of following medical protocols.

This book is intended as a basic reference for medical students, teachers, and general readers interested in the application of logic, philosophy and scientific principles in medicine.

• Language: English
• Publisher: Bentham Science Publishers
• Release date: Dec 1, 2022
• ISBN: 9789815050806

Book preview

Introduction

Zekâi Şen

Abstract

Basic knowledge and information are acquired through the language in the family, society and education, which should be based on philosophy and logical principles. In the field of medicine, a dialog can be established between the doctor and the patient for diagnosis with linguistic (verbal, oral) information exchange rather than mathematical expressions. This chapter presents rational thinking with logical principles, preferably combining the basic principles of philosophy in medicine with the treatment of uncertainty, the results of which are presented according to the usual bivalent (crisp, two-value) logic. The necessary and effective structural steps of rational use of language are presented based on verbal knowledge and uncertainties in information production. It is emphasized that innovative ideas, procedures and methods are possible through research and development activities, if the language, philosophy, and logic principles are observed for the most reasonable cases, even with approximate decisions.

Keywords: Education, Language, Logic, Medicine, Philosophy.

Medicine and philosophy are integrated and almost similar, as Aristotle (382-323 BC) mentioned in many of his writings that the work of medical doctors and philosophers is closely similar. On the other hand, Hippocrates (460-375 BC) said:

Medicine cannot be without medical truth, and philosophy cannot be without medical truth.

"All traditional logic habitually assumes that precise symbols are being employed. It is, therefore, not applicable to this terrestrial life but only to an imagined celestial existence." (Russell, 1923).

"So far as the law of mathematics refers to reality, they are not certain. And so far as they are certain, they do not refer to reality. "

(Einstein, 1925).

As the complexity of a system increases, our ability to make precise and yet significant statements about its behavior diminishes until a threshold is reached beyond which precision and significance (or relevance) become almost mutually exclusive characteristics."

(Lotfi Asker Zadeh, 1965).

1.1. General

Social, medical, cultural, economical and environmental disciplines require linguistic and verbal discussions before a numerical database treatment, through the principles of philosophical thinking and logical inference. Preliminary data between a physician and patient is verbal, in addition to simple temperature and blood pressure measurements. The basic information is sensed and learned orally by the etymologic and epistemological contents of sentences. It is not necessary that each sentence reflect reasonably causative and effective answers for information contents. The ones with unanswered questions give each person a chance to think about the issue deeply to reach a better evolution than before. If the predicate is related to the consequent part in a logical sentence, i.e., proposition, the rational consequences are reachable; otherwise, one must gather more information through discussions, debates and comments for a better assessment of the predicate-consequent relationship. For example, in medical treatments after the diagnostic decisions, there is always uncertainty in terms of vagueness, bluntness, incompleteness and fuzziness, which include skepticism and doubts. These are the components of philosophical thinking for a possible solution alternative (Chapters 5 and 6).

In order to transmit and receive information, speaking, listening, writing and reading, and many actions that are linguistically more human, are parts of language, which help to communicate. Language is the essential tool for the philosophy of science and the execution of knowledge and information at times of request. The linguistical entities provide almost instantaneous graphs of the information in the forms of objects, facts and realities.

Johansson and Lynøe (2008) explained perceptions based on talking, listening, writing, and reading (linguistic acts) as intentional communication elements. They exist by inter actions among three elements; act, content and object. For example, when one reads a physician's report about his heart problem explaining the specific features, the reading is an action. In general, any reading act about the heart problem and its properties is referred to as the content in terms of assertions based on logical propositions. According to crisp (bivalent) logic, if a proposition is false, there is no logically intentional object. On the contrary, if it is completely accurate, then there is a logically acceptable object. On the other hand, partial accuracy refers to the intentional object in the fuzzy logic domain (Chapter 8).

The three integral constituents are body (health), mind (the ability to think and make decisions) and spirit (sensitivity and responsiveness, awareness and the ability to stay alert, passionate desire to get out of the 'attractor' of egocentric thoughts and desires, compassion and love, the more subtle and spiritual reality). The simultaneous activation ('ignition') is called a consciousness resonance.

The main purpose of this book is to clarify verbal uncertain expressions by the recommendation of science, philosophical and logical principles through various intermingled chapters concerning medical issues.

1.2. Language and education system

The dynamic education system in any society should focus on scientific researches, developments, innovative improvements and productions. Instead of statically planned lessons in every branch of science, it is suggested that scientific philosophical thinking, logical principles, especially fuzzy logic, uncertainty principles, and some geometry (from sketches, shapes, Figs graphs, images) should be included among the basic foundations of education before mathematics courses.

Al-Farabi (870-950) believed in the role of language in human’s social life and in conveying information, asking questions and resolving conflicts by describing distinctions and classifications similar to Aristoteles (BC 384-322), but in a more advanced way. The way to understand is through language, in which one can express ideas and discuss with other individuals, thereby distributing basic information about the topic of interest.

Language consists of words and sentences, provides expressions and is the umbrella of the climate of thought (Chapter 2). The first foundation of any language is words that reflect materialist or imaginary issues existing or non-existent, as well as the essence of ideas that guide comprehension and expression. In the materialistic world, every word is the name of a subject depending on its form and geometry because the word helps to imagine the living form of the subject in the human mind. In general, each word has an etymological and epistemological background, which forms the basis of the logical and rational load for meaningful and understandable linguistic expressions that generate shape, geometry, and logical traces in the mind and memory of the individual. Depending on their thinking abilities, anyone can devise ideas in the form of

diagrams, sketches, pictures, images and Figs to convey the message to others (Chapters 2 and 4).

Human thoughts are concentrated in terminological words depending on each discipline, such as every expert translating medicine and thoughts into words and sentences for better understanding. Correction and development of understanding can be increased by knowing the epistemic and etymological contents of each word that is systematically combined into sentences depending on the grammatical feature of the language. An idea can be explained in simpler language terms for better understanding rather than complex expressions. One of the main means of possible enlightenment in a society is the master of a common language that spreads ideas across different classes and disciplines. The development of ideas in a more scientific direction is possible through frequent information exchange and discussions, reading and writing. Knowledge is the result of the ability to think or comprehend, and, thus, to distinguish right from wrong (Chapter 2).

Fig. (1.1))

Structural steps of language.

Among the traditions of a nation, there are meaningful words that support the common understanding that helps to generate pronunciation, spelling and grammar, otherwise, the disruption of this tradition destroys communication. As a result, philosophical thought and logical expositions of rules cannot survive in such a society. The term philosophy has a wide meaning, from a cloudy speculative fantasy (fuzzy) to a bit of formal logic (bivalent). (Fig 1.1) shows that the basis of all uncertainty components is language, which needs philosophical and logical principles for its enrichment that lead to rationally reasonable inferences.

The flaws in any traditional education system can be stated as follows (Şen, 2014).

Teachers’ authoritative responsibilities based on law and traditional rules may not allow for productive rational thinking. In such an education system, any answer is definitive, i.e., based on bivalent Aristotelian (BC 384-322) logic without any reference to Al-Farabi (870-950) logic (probability) or fuzzy logic (Zadeh, 1967).

Hardware is considered only indispensable, and software based on the philosophy and logic of science is used unconsciously. Thus, the way is paved for memorization, transportation, copy-teach and mechanical education system.

The information is taken from the books without efficiently critical inquiry; with certain concepts, regardless of any element of uncertainty.

Scientific concepts are not thought, and therefore, a one-sided thought pattern is followed, and a single answer is given to each problem with 100% scientific accuracy, which everyone should accept without hesitation.

Scientific assumptions, hypotheses and idealizations that do not have such validity, especially in medical sciences, are preserved strictly. Scientific results are considered correct under a number of preconditioned assumptions. There is always a certain amount of uncertainty in medical research case studies.

On the other hand, the followings are the key points of a modern and innovative educational system.

Traditional and classical elements should be minimized and even removed from an innovative education system. Authorizeable teachers should be knowledgeable, empowered and capable of giving dynamic information.

Teacher should not be completely dependent on educational tools, and the students should try to push the teacher for more information on the margins of the material presented through questions and discussions.

It should not be forgotten that each scientific result is subject to uncertainty and doubt for further refinements leading to innovative idea generations.

Logical propositions containing premises are formed between subcategories of causal variables, and then logical and rational consequences of the subject variable are added to each of these premises.

It is useful to give a common assignment to ensure students’ understanding and to ask for a solution to the problem with their individual abilities and linguistic background.

1.3. Historical Uncertainty Discussions

Religion, science and technology were, in retrospect, tacitly seen as an integrated whole. Thus, although the ancient agricultural societies of Mesopotamia and Egypt were not centrally interested in acquiring knowledge based on empirical evidence, they nevertheless produced such knowledge (Chapter 3). It was left to the ancient Greek natural philosophers (for example, Thales of Miletus, 624-546 BC) to be the first to adopt a purely philosophical and logical attitude towards knowledge of nature. This knowledge was important for sailors when Ptolemy (100-170) theorized about how the planets and the stars move around the Earth. At night, sailors found their way through the positions of the celestial bodies (Johansson and Lynøe, 2008).

Later, great scientists such as Galileo (1562-1642) and Newton (1643-1727) thought and wrote about purely philosophical issues. Conversely, great philosophers such as Descartes (1596-1620) and Leibniz (1646-1716) made lasting contributions to the fields of physics and differential mathematics. In the period when the Islamic culture was the most advanced scientific-philosophical culture in the world, important personalities such as Ibn Sina (Avicenna) (970-1037), Ibn Rushd (Averroes) (1126-1198) and Zakaria Al-Rhazes (854-925), contributed to medicine (Chapter 3).

Newton (1643-1727) used a less restrictive understanding of scientific knowledge in natural philosophy than philosopher John Locke (1632-1704). In his understanding, science required moral or practical certainty rather than metaphysics or absolute certainty. This is to say that scientific statements are inherently fuzzy in character. They had different understandings of what kind of uncertainty was necessary for scientific knowledge. Locke’s concept of scientific knowledge included absolute certainty that could not be a matter of degree. He succeeded in making a sharp distinction between scientific knowledge on the one hand, and judgment on the other with his term for what he called probable opinion. Here again, the possible view is valid only in the case of ambiguous knowledge, that is, when scientific statements are fuzzy in their structures. On the other hand, Newton’s (1643-1727) practical certainty is a matter of degree, and to accept degrees of certainty is to accept degrees of probability. For this reason, in Newton’s (1643-1727) philosophy, a sharp distinction could not be maintained between scientific knowledge and a possible view of understanding. Therefore, it is necessary to use fuzzy statements as intermediate expressions. In any case, Newton agreed that his knowledge was not absolute certainty until the integrity of his empirical natural philosophy provided true knowledge. To sustain his distinction, he had to supplement logic with rhetoric. Rhetorical statements are vague or imprecise sets of information in the form of fuzzy sets (Chapter 8).

The most well-known reasoning is probabilistic reasoning in the sense that it produces results that have this or that degree of certainty, and thus one or another degree of probability and yet still have one or another degree of ambiguity. Later, in the century, with the idea of using evidence, and in particular empirical evidence, to argue for truth or at least believability, the concept of probability become identified with the idea that something is believable or unbelievable in the light of the evidence. All these last expressions are teachable in terms of fuzzy sets (Zadeh, 1968).

Not every conclusion from probable reasoning is acceptable, but only some have vague degrees. Therefore, for any probable reasoning, it is necessary to have a measure of when and why such reasoning is acceptable. It is also necessary to find ways to measure the degree of uncertainty that indicates how measurable an outcome is. To this end, Huygens (1629-1695) first published an account in 1675 to show the treatment of quantitative probabilistic reasoning in games of chance. His treatment lacked words for the customary use of illustrating concepts of probability.

On the other hand, Leibniz (1646-1716) stated that in order to support scientific achievements, researchers must accept that absolute certainty is an ideal they can reach. The degrees of probability should be accepted and associated with knowledge during scientific studies. Since the objective definition of probabilities requires measurements that are impossible to have at the stage of scientific thinking. The best that can be done is to add subjective probability values to each statement especially based on many years of experience and expert opinions. This last sentence is particularly appropriate in medical research, where empirical and experimental data are extensively available in each clinical case study. However, it is preferable and better to express uncertainties in any statement in terms of ambiguity by fuzzy sets and membership degree MD) attachments to each element in the set (Chapter 8). Therefore, reasoning with probable conclusions may be acceptable rather than dismissed. In fact, probability is a relation between the evidence disclosed by researchers and the conclusions they draw. This is similar to a doctor inferring probability from the information given by a patient. It is also possible to say that there is a legal model originally given by Al-Farabi (872-950) for probable reasoning logic. As Leibniz (1646-1716) said, we need a new logic to know the degrees of probability, because it is necessary for judging the evidence of factual and moral issues. Therefore, a new logic, such as fuzzy logic, is developed in the 1960s (Zadeh, 1968). Recently, emerging fuzzy logic principles can fulfill the linguistic background of any formulation, algorithm, and equation (Zadeh, 1972, 1973, 1974, 1975). David Hume (1711-1776) claimed that

"all reasoning concerning matter of fact seems to be founded on the reflection of cause and effect and the probable arguments with which Bayes was concerned can indeed be understood as reasoning from effect to cause".

Keynes (1921), on the other hand, thought that probabilities were not merely relative frequencies based on observation. Moreover, for him, probabilities were degrees of belief, and it was necessary not only to attribute probabilities primarily to propositions, but also to recognize that propositions are always probable in relative to other propositions (Chapter 9). He endorsed the conceptual or classical idea of probability. Russell (1948) said that degrees of rational belief could be determined by reason.

A degree of rational belief is a subjective measure of the logical relations between antecedents and the consequences. In medicine, such probabilities circle, but they are not just degrees of belief, because they are based on experience and expert opinion.

When the evidence changes, degrees of belief also change due to uncertainty in thought rather than in experience, for they are logical relations of partial entailment between propositions expressing conclusions for which one has degrees of belief. Probabilities as degrees of belief are subjective; they represent psychological states (Ramsey, 1978). It is important to understand the rationality of probability judgments that derive from scientific research. They are dependent on whether they correspond to something external to them or whether they can be derived from a supposedly objective principle of indifference, but rather, on the relation of the beliefs to one another.

Russell states that the purpose of inductive arguments is to make their conclusions likely true given the correctness of their premises. In deductive arguments, however, we want the conclusions to be true, given the truth of their premises.

Instead of claiming that regularity happens in all cases, sometimes it happens only in a certain percentage. If a percentage is given or otherwise, a quantitative statement about the relation of one event to another, this statement is called a statistical law (Carnap, 1995).

The concepts of science and everyday life can be considered in three main groups as classificatory, comparative, and quantitative. A classificatory concept simply means the allocation of an object in a certain class. They vary widely for information about an object. For example, if someone says that, an object is blue, hot, or cubical; they make relatively poor statements about the object. All these words contain uncertainty and as a result, they can be easily expressed by fuzzy subsets. By placing the object in a narrower class, information increases, although it remains relatively modest. Such narrowness corresponds to the narrowness of fuzzy subsets, which is equivalent to the increase of information content. For example, the statement that an object is a living organism is very vague, but it is an animal, says a little more. As classes continue to shrink, we have an increasing amount of fuzzy sets but still relatively little information. Comparative concepts are more effective in transferring knowledge. For example, this object is hotter than that object; gives more information than classifier concepts. The third type of scientific concept is quantitative because of measurement.

The main conclusions are that the scientific knowledge cannot be completely verifiable or falsifiable, but always fuzzy, which provides potential for further research. As a general conclusion, science and any quality associated with it, are never completely verifiable or falsifiable, but can always be fuzzy, and so further developments are always valid for places and societies in the form of intuition, traditional science, and occasional revolutionary science (Kuhn, 1970).

Deterministic science and physics were developed with the exclusion of uncertainty through a set of idealistic, restrictive and simplistic assumptions. Today, there are elements of uncertainty in almost every branch of human activity and especially in the field of medicine. Uncertainty principles include Newtonian physics, Euclidian geometry, non-linear mathematical equations, and quantum physics, fractal geometry, chaos theory and fuzzy logic, although they are crisp in Aristotelian (BC 384-322) logic (Peitgen, 2004; Elwan, 2014). On the other hand, some other subjects remained uncertain for centuries, such as the earth and medical sciences, sociology, physiology, human behavior and many more that the reader can think of. The classical education system was in domination by deterministic principles to the extent that science explained reality. Probability, statistics and stochastic time series methodologies have made further advances in numerical analysis (Chapter 9).

1.4. Philosophy Principles

The first problem encountered when trying to define what is meant by a philosophy of science, is the notorious ambiguity of the term "philosophy (Ernan, 1983). Science itself is objective, but its foundation as philosophy is uncertain, imprecise, fuzzy and rather vague. How can scientific progress be possible if science and its philosophy are uncertain? However, the pictures of reality are becoming more different than ever. In particular, many scientific theories believed to be true, have turned out to be false, or there is much debate over their verifications or falsifications. In the field of scientific philosophy, scientists are quite uneasy about testing and setting boundaries to distinguish scientific knowledge from pseudo-scientific. It is not possible to have scientific thought without knowing or at least even unconsciously living the philosophical progress that provides complete freedom in scientific thought. Although many academics today think that they produce scientific articles without considering the philosophical components in their approaches, in fact, their procedures involve scientific philosophical thinking. The complete freedom of philosophical thought provides many scenarios about any relevant phenomenon, but logic removes an enormous amount of them based on results contrary to general philosophy or at least to common sense. Common sense is not always reliable, but it is common for all people to conclude or decide on a case. Philosophers of science seek the study of general scientific properties that are often relevant as a knowledge-producing activity. According to rational explanations, it is worthy to consider philosophically and logically verification procedures, the correctness of theories and patterns of development combined with the truthfulness of theories. A detailed account of the origin of the distinction between science and philosophy is presented by Frank (1952).

1.4.1. Philosophy and Medicine

Philosophy and medicine are twins; each needs the other for improvement in thoughts, diagnosis, treatment, healing and inferences from ambiguous statements. Although logical principles are approximate products of reasoning, they are like teachers who are experts in reaching rational conclusions. Caplan (1992) has asked the question, Is there a philosophy of medicine? He also expressed the relationship between philosophical principles and medicine. However, the author of this book supports the fruitful idea that philosophy in medicine is necessary at every stage of medical treatment. The philosophy and logic seek to reach the truth; the purpose of medicine is to cure diseases to maintain the health of the body. Thinking and then applying logical principles are necessary steps to reduce uncertainty in the medical discipline. In particular, the history of medicine is filled with the evaluations made in medicine from the ancient Greek civilization and all civilizations after it to the present day (Chapter 3). Even though medical research has advanced in an unprecedented way, there remains the question What is the disease? There are basic questions that have not found definitive answers, such as "What are the chances of cancer curement? Only very objective scientific tools cannot solve health problems, there are other dimensions in the human body, such as mind and spirit, that require compassion, culture, moral advice, ethics and social environment. In order to fulfill all the aforementioned medical explanations, philosophical epistemology, ethics, logic and metaphysical principles are needed, as explained in the various chapters of this book. The role of philosophy is to verbally discuss rather vague facts, misunderstandings and critical concepts (Chapters 5 and 6), which can then be translated into rational statements in propositions through logical principles (Chapters 7 and 8).

Tosam (2014) argued that one of the weaknesses of modern Western medicine is its over-dependence on Cartesian ontology, which sees the human body as machines to be studied with scientific logic, and the physician as a technician whose aim is to repair dysfunctional bodies. This modern metaphysical perspective neglected the patient as a subjective being. This deficiency cannot be remedied without a revision of the Cartesian reductionist worldview. A more detailed explanation of the relationship between philosophy and medicine is available in his paper.

The main concern of medicine is to bring dysfunctional operations of the human body and mind and to retreat them into the proper order to satisfy the body and mind for comfort, peace and reliability. Treatment and medical relationships for the art of the human body and mind are listed as diagnosis, treatment and healing. Janicek and Hitchcock (2004) explained this point by stating that medicine is the art and science of diagnosing, treating, preventing and maintaining health Is it not possible to develop thoughts without knowing the epistemological background of each understanding and criticizing it philosophically? (Chapter 4). In any discipline, including medicine, collecting information is not enough, but thoughts that require the application of philosophical and logical principles are essential to be achieved through refinements of crucial and critical thinking, imagination, experimentation and expert opinion.

Medicine is not concerned with universal physical phenomena that scientific principles can only control; its task is a man in general and each individual in particular. Therefore, medical treatment given to one person cannot generally be administered to another patient in the same way (Chapter 8). Today, although technologically developed tools are at the service of physicians for better diagnosis, since the results of these tools are different for each patient, fuzzy logic rather than bivalent (crisp) logic comes to the fore in medical sciences (Zadeh, 1968). Still, the best diagnoses are based on practical decisions after collecting all valid information. Unfortunately, today’s medical treatments rely only on objective scientific materialist body parts, without considering other dimensions such as mind, and spirit. Although science itself is a product of philosophy, its philosophical foundations have been partly forgotten, and highly decisive methodologies have been used to solve medical problems. Especially, in the medical business, there are rather vague principles rather than deterministic ones in each case of health care, and therefore, philosophical thinking combined with logical principles helps understand the basic concepts so that the physician can serve the patient during the recovery process. The physician can even understand some of the patient’s feelings from facial impressions (physiognomy); accordingly, depending on philosophical principles, he can give oral calming advice before medical treatment. Avicenna (970-1037) mentioned facial features and made it one of the second practical branches after medicine, astrology and imaginative interpretation, magic and alchemy (Thomann, 1996).

1.5. Logic

There are philosophical, rational or irrational expressions regarding every human thought in daily life communications, but the logical ones have a sentence structure in the form of propositions with a rational combination of cause and effect. This means that there is reasonable and acceptable judgment consideration that leads to widely acceptable statements. These statements have explicitly or implicitly if (reasons) then (consequences) implications (Chapters 7 and 8).

Logic defines rational prescriptions from the ocean of philosophy. Its primary task is to generate systems and criteria for distinguishing rational arguments expressing inferences from uncertain ones; due to these processes, new claims are produced from those that have already been established. It provides a mechanism for expanding knowledge, understanding, good reasoning and explanation. The following points are among a few that are the target of logical principles.

The prudent use of authorized knowledge and the solutions are not completely dependent on information devices, the scientist’s attempt to break the marginal limits of common certainty through discussions and questions with logical principles.

Any scientific conclusion is subject to uncertainty and doubt, and therefore, further improvement is required through rational considerations that lead to innovative ideas and changes.

Keeping logical principles, rules and preliminary philosophical steps on the agenda by scientists to each problem can be solved with expert contributions.

Scientific thinking should be directed towards the falsifiability of conclusions or theories rather than readily and easily acceptable conclusions. This can be achieved first by logical principles and then by experimentation.

For practical medicine, Stanley and Campos (2013) noted that establishing the diagnosis is a crucial aspect because of relatively little logical and pedagogical attention. Therefore, it is necessary to consider the logic of medical diagnosis in order to reach conclusions that are more rational.

Recently, a very detailed explanation of Al-Farabi’s (870-950) views on principles of logic is offered by Hodges and Therese-Anne (2020). Al-Farabi (870-950) argued against Galen that logic in terms of probability is useful in practical arts as medicine, agriculture, and nautical where actual outcomes have to be predicted (Schacht and Meyerhof, 1937). This seems like the confusion between possibility and probability at first glance. However, more likely Al-Farabi (870-950) believed that the laws of modal logic could be fine-tuned to work with Probably rather than a modal operator. Al-Farabi (870-950) says that Necessarily every A is a B and Like most As are Bs is treated as equivalents. Nevertheless, would not make a correlation between Probably with Necessarily instead of Possibly?

There is further evidence that Al-Farabi (870-950) experimented with other sentence forms in modal logic. Both Avicenna (Street, 2001, 2015) and Averroes (1126-1198) quote Al-Farabi (870-950), for example, taking into account syllogism propositions that include insofar as, Every A can be a B insofar as it is a B. Al-Farabi (870-959) wrote some necessary and sufficient conditions for certainty (López-Farjeat, 2018; Black, 2006). He also points to the semantic range of acquisition: either through a certain proof or persuasion through.

1.5.1. Bivalent (Two-Value) Logic

The term philosophy has a wide meaning, from a cloudy speculative fantasy to a piece of formal logic. Formal logic in philosophy until recently is considered as the Aristotelian (BC 384-322) bivalent logic of completely defined classes as true or false; positive or negative; black or white; beautiful or ugly, etc. All scientific hypotheses, theories and ideas are primarily measured based on this logic, and as a result, classical scientists emerged with dogmatic beliefs. The reason that so many academicians do not qualify as scientists is due to the certain nature of the binary logic. In this logical field, even cloudy, ambiguous, uncertain, and imprecise qualities are classified into strictly distinctive and mutually exclusive sections, and only one alternative is considered scientific (Chapters 2 and 7). None of the scientific knowledge is accountable as completely crisp without doubt; otherwise, scientific development cannot continue. Scientific development is not due to the exactness of the knowledge but rather due to vague characteristics. The terms vague, imprecise, uncertain, blurred, and cloudy are altogether referred to as fuzzy information (Zadeh, 1968). After the beneficial contributions of bivalent logic over the centuries, this book additionally proposes

the use of fuzzy logic to determine the boundaries of scientific knowledge, especially in medical sciences.

1.5.2. Fuzzy Logic

To clarify the distinction between formal bivalent (classical), symbolic (mathematical) and fuzzy logic, it should be noted that if something is true or thought to be true, it is given the number 1 and its alternative as 0, which implies the impossibility of intermediate situations. There is no mixture of the two states. In other words, partially right or wrong, which is the basis of human thought, is not taken into account. Fuzzy logic even assigns degrees of belief (degree of confirmation or falsification) to a scientific work that takes values between 0 and 1, inclusive. The verifiability of scientific knowledge or theories by logical positivism means that the limits of science are equal to 1, without including Farabi's (870-950) probabilistic proposition or Popper's (2012) falsification principle (Chapter 5). The conflict between verifiability and falsifiability of scientific theories involves fuzzy philosophical underpinnings, but many philosophers of science have come to solutions with the bivalent logic of clarity that goes against the nature of scientific development. Unfortunately, fuzzy philosophy of science has not been introduced sufficiently so far in the education system, although many philosophers of science have tried to resolve this problem by introducing the argument of probability (Carnap, 1987) and sometimes the possibility of the limits of scientific knowledge and scientific development has entered the literature sufficiently. Therefore, one of this book's purposes, especially in Chapter 8, is to explain fuzzy logic in the demarcation of medical knowledge and scientific progress. Scientists are not entirely objective in justifying scientific boundaries or progress, but the components of fuzzy logic are the impetus for the generation of new theories. The entire verifiability of the scientific rule can be tested by the fuzzy inference engine for better understanding and dissemination of knowledge (Chapter 3). In fact, all cases in many disciplines, especially medicine, have fuzzy features. The foundations of scientific philosophy include embedded fuzzy components. The dogmatic nature of scientific knowledge or belief gives the impression that science, the fruits of formal