




































REVIEWING MODERN SCIENTIFIC KNOWLEDGE WITHIN THE SCOPE OF 

NIETZSCHE’S IRRATIONALISM 

Oreoluwa Idris ADESANYA 

 

Abstract 

Human knowledge has been constrained into two major bifurcations; knowledge based on 

factual experience and those based on value, instincts and intuitions. Scientific knowledge 

is claimed to be based on empirically verifiable data; thereby being considered as the most 

reliable system of inquiry ever developed by human civilizations. Scientific knowledge is 

esteemed to be a systematic inquiry, which emphasizes the superiority of human reason 

over human intuitions, instincts and impulses. However, Friedrich Nietzsche expresses 

strong disgust for the over-glorification and exaltation of reason over those elements of 

human nature that serve as alternative sources of knowledge such as dark strivings, 

vitalism, intuitions, instincts and impulses. Nietzsche criticizes all forms of system- 

building as expressed in the universalization of fixed scientific methods, universal 

conceptions of truth and knowledge and the very idea of unquestionable religious morality 

and social norms. For Nietzsche, what is needed for the liberation of the human soul; and 

the realization of the ―will to power‖, is the abandonment of reason and the celebration of 

the dark instincts, creative intuitions and animalistic outbursts, which represent the 

irrational  part  of  human  nature.  The  ―will‖,  which  is  a  symbol  of  irrationality,  defines 

human nature in its crudest form. This work proposes two major contentions: the first is 

that scientific knowledge is exclusive, as it denies the authenticity, validity and efficacy of 

other non-rational and non-systematic modes of knowing. The second contention of the 

paper is that there exist, non-rational, authentic, valid and efficacious elements of human 

nature that serve as reliable modes of apprehending knowledge, beneath and beyond 

rational and systematic epistemic modes, which are elaborated by Friedrich Nietzsche in 

his philosophical irrationalism. 

Keywords: irrational, rational, science, Nietzsche, system, method, knowledge. 

 

1. Introduction 

The modern civilized man is totally overwhelmed by the dominance of rationalism. He 

embraces reason as the major faculty that is responsible for his choices and decisions. He 

is totally in praise of science and emphasizes the rational part of his nature at the expense 

of a part which is more indebt in his nature (i.e. the human will). Modern scientific 

knowledge is being projected to be based on the principles of rationality and objectivity, 

thereby representing the only form of reliable knowledge available to man. This is exactly 

the image that the scientific community likes to project of itself, which is considered by 

Wilhelm Newton-Smith, as that of ―rationality per excellence‖ (Newton-Smith, 2003). p.1. 

According to Newton-Smith, the ―scientific community sees itself as the very paradigm of 



Aquino Journal of Philosophy, Vol. 1(1), 

 

institutionalized rationality. It is taken to be in possession of something, the scientific 

method, which generates a ‗logic of justification‘‖ (Newton-Smith, 2003). The assumption 

that science represents the paradigm of institutionalized rationality, as being commonly 

admitted and accepted by the scientific community, implies that there is ‗something 

special‘ about science, which distinguishes it from other human intellectual endeavors, 

such as philosophy, theology, history and the rest. 
 

However, most members of the scientific community are of the opinion that a 

characteristic  feature  of  science,  which  makes  it  ‗special‘,  is  the  ―logic  of  discovery‖, 

which serves as privileged method of formulating and validating theories, involving 

continuous problem-solving activities. The overwhelming glorification of science over 

other human activities derives in large part from the successes of recent science and 

modern physics in particular. The exclusivity of scientific knowledge in contemporary 

times was triggered in large part by the emergence of logical positivism in the 20
th

 

Century, which was a movement that bifurcated knowledge into two, by introducing a 

criterion of significance: known as the verifiability criterion. The verifiability criterion 

affirms that a piece of knowledge or intellectual enterprise is only to be regarded as 

meaningful when it either passes the test of empirical validation or is explainable by 

definition (Ayer, 1959). The verifiability criterion proposes that the meaningfulness, truth 

and validity of a statement can only be deduced from the possibility of stating the facts 

that make them possible. A prominent logical positivist, Moritz Schlick, espouses this 

view,  by  stating  in  clear  terms  that:  ―It  is  the  first  step  of  any  philosophizing,  and  the 

foundation of all reflection, to see that it is simply impossible to give the meaning of any 

statement except by describing the fact which must exist if the statement is to be true. If it 

does not exist then the statement is false‖ (Schlick, 1932), p. 88. An implication of the  

logical positivist‘s contention on the place of empirical verification for modern science is 

that science is an intellectual enterprise that is based on rationality and the facts of 

experience. Scientific claims must therefore by testable by experience. 
 

However, Friedrich Nietzsche, being a proponent of philosophical irrationalism, discredits 

the scientific and positivist claim that reason and experience alone determines reliable 

knowledge, while affirming the irrational elements of human cognition, such as ―the will‖, 

instinct, intuition, emotion, dark strivings and the rest, as bases for reliable knowledge 

(Nietzsche, 2010). In this paper, we attempt an exposition of the movement of 

irrationalism, synthesizing and contrasting it with its counterpart; rationalism. The scope 

of the paper is to project Nietzsche as a prominent figure in the dethronement of reason, 

and the embracement of the non-rational part of human nature, as the initiator of 

postmodernism, and as well discuss the implications of Nietzsche‘s irrationalism for the 

enterprise of modern science. This paper shall also attempt a review of the major 

contentions of modern science within the scope of the irrationalist pretensions of 

Nietzsche‘s philosophy. 



Adesanya Reviewing Modern Scientific Knowledge … 

 
2. The Rational Image of Science 

Modern science is being widely conceived as the paradigm of rationality and the sole 

model of truth, which possesses the exclusive methods of arriving at reliable knowledge 

and problem-solving. Science is generally considered as ―any ―systematized‖, ―organized‖ or  

―classified‖  body  of  knowledge  which  has  been  critically  tested  and  is  beyond 

reasonable doubt‖ (Nagel, 1961), p. 3. Therefore, for any piece of knowledge to be tagged 

‗scientific‘, it must result from a systematized, organized and classified procedure, which 

is guided by an underlying logic of discovery, mostly described as a method. Jack 

Aigbodioh identifies four characteristic features of science, which include the fact that 

science is said to be specific, public, impersonal and objective (1997), p. 3. The specificity 

of natural science is evident in the fact that science solely enquires into particular and 

identifiable objects which are observable in the physical world of experience, rather than 

merely abstract or metaphysical ideas which are beyond the realm of observable reality. 

Science is being considered as being able to provide us with exact explanations of the 

nature of phenomena around us as they actually are. The enterprise of science is regarded 

as being public in character, owing to the fact that the methods, techniques and procedures 

of science are exoteric, rather than being esoteric. This implies that scientific knowledge 

can be taught to the generality of persons, and can be interpersonally or inter-subjectively 

verifiable, rather than being known by a select few who hold an exclusive right to such 

knowledge. Similar to the public character of science is the claim that the enterprise of 

natural science is impersonal. Science is often considered as being devoid of idiosyncratic, 

sentimental,   and   imaginative   beliefs   or   ideas,   but   is   rather   ―dispassionate   and 

unprejudiced‖ (Aigbodioh, 1997), p. 4. Science bases its explanations on factual judgments 

rather than value judgments. 

 

The objective character of scientific claims, theories, principles and laws lies in the fact 

that they are all drawn from the concrete or material facts of the physical world of 

everyday perceptual experience. Science is said to be objective because it is entirely based 

on facts. The factual nature of scientific propositions is given a clearer picture by Alan 

Chalmers, when he writes that: ―When it is claimed that science is special because it is 

based on the facts, the facts are presumed to be claims about the world that can be directly 

established by a careful, unprejudiced use of the senses. Science is to be based on what we 

can see, hear and touch rather than on personal opinions or speculative imaginings‖ (1999), 

p. 1. Moreover, the specific, public, impersonal and objective characters of the sciences  

are  said  to  confer  on  them  ―the  amazing  power  to  uncover  the  truth  about  the world as 

it actually is, constituting them into knowledge par excellence‖ (Aigbodioh, 1997), p. 5. 
 

However, the received view of science that scientific knowledge is derived from the facts 

of the physical world of perception is often attributed to two schools of thought, namely: 

empiricism and logical positivism (Chalmers, 1999), p. 3. The British empiricists, notably, 



Aquino Journal of Philosophy, Vol. 1(1), 

 

John Locke, George Berkeley, and David Hume share the common view that all 

knowledge are derived from ideas in the mind which are implanted by sensory perception. 

These ideas are regarded by David Hume as sense impressions which are products of 

perceptions of external physical objects (Hume, 1975). The external physical objects 

thereby serve as the facts, which every scientific theory should attempt to fit. The logical 

positivists, such as Alfred Jules Ayer, Carl G. Hempel, Rudolf Carnap, Moritz Schlick, 

and the rest, also subscribe to the empiricist view that scientific knowledge, and 

knowledge generally is primarily derived from the facts of experience (Ayer, 1959). The 

logical positivists were more interested in the form of the logical relationship between 

scientific knowledge and the facts. The positions of the British empiricists and the logical 

positivists imply that modern scientific thinking is firmly based on the principles of 

rationality, which include: objectivity, impersonality, precision, soundness, validity, 

deduction, and induction. 

 

3. Philosophical Irrationalism 

The age of Enlightenment brought with it, an appraisal of reason as the determinant factor 

for human personality and guide to all human endeavors. During this age, reason was 

regarded as sovereign. Philosophers therefore, defined human beings by their capacity to 

think critically. This thought system was challenged by some thinkers in the late 

nineteenth century. The Enlightenment conception of human rationality was questioned, 

while the irrational aspects of human nature were emphasized. These thinkers now saw 

existential elements of human life such as blind strivings, animal instincts as the primary 

fact of human existence. For them, reason exercised a very limited influence over human 

conduct and that much more than logical consciousness, all forces below the surfaces, 

such as: impulses, drives, instincts, feeling, and will determine human behavior (Russell, 

1945). Irrationalism is a nineteenth century and early twentieth century philosophical 

movement which advocated the non-rational aspects of human behavior as being 

necessary for apprehending human life. That human life could be better explained and 

understood by expanding it beyond the rational to it fuller dimensions. Although, in 

philosophical history, irrationalists could be found before the nineteenth century, 

especially in the predominantly rationalistic Ancient Greek culture in the works of a poets 

like Pinder, dramatists, and even in such philosophers as Pythagoras, Empedocles and 

Plato, who all share a Dionysian (instinctive) influence (Perry, 1992). 
 

Irrationalism is a multi-faceted reaction against the dominance of reason in philosophical 

history, with various strands, and orientations on the role played by reason in human 

behavior. Some thinkers recognize the weakness of reason, continued to value it and 

sought to preserve it as an essential ingredient of civilized life, while for others, the 

creative potential of the irrational aspect of human behavior is to be emphasized. They 

urged the embracing of the feelings which they considered vital to artistic creativity and a 

richer existence. There are still others who strongly oppose the claim of scientists and the 



Adesanya Reviewing Modern Scientific Knowledge … 

 

positivists that only mathematical truths or principles and analytical reason was the 

supreme arbiter of knowledge and the only part to certainty. They argued otherwise that 

the truths discovered by the intellect were less profound than those grasped by our interior 

sentiments. ―Like the romantics, proponents of the non-rational placed more reliance on 

feeling, spontaneity, instinct, intuition, and other non-rational sources of knowledge than 

on reason. They belittled the intellect‘s attempts to comprehend reality, scorned the 

liberal-rational tradition, praised outbursts of the irrational, and in some instances lauded 

violence‖ (Perry, 1992). In fact, new insights were gained into the irrational side of human 

nature which along with the growing assault on reason influenced political life hugely. In 

later decades, the various currents of irrationalism mentioned above became ideologized 

and  politicized  by  ―unscrupulous  demagogues‖  who  sought  to  mobilize  and  manipulate 

the masses, with their emphasis on a chiefly Aristotelian society (Perry, 1992). A typical 

example of such ideological orientation was the fascist movements, which openly 

denigrated reason and exalted race, blood, action, and will. This runs against the position 

of nineteenth century liberals who held that reason had triumphed in all of human affairs. 
 

In early modern philosophy, even when Cartesian rationalism was developing, Blaise 

Pascal turned from reason to an Augustinian faith, claiming that the ―heart has its reasons‖ 

unknown to reason itself. Irrationalism emphasized things about the life of the spirit and 

human history that could not be dealt with or handled by rational methods of science 

(Frankfurt, 1982), p. 92. The likes of Charles Darwin and later Sigmund Freud made 

irrationalism a movement interested in the exploration of biological and subconscious 

roots of human experience. Philosophical theories and movements like pragmatism, 

existentialism, and vitalism (or ―life philosophy‖) all arose as expressions of this expanded 

view of human life and thought (Stumpf, 2003). Arthur Schopenhauer, a typical nineteenth 

century irrationalist, exposited the idea of voluntarism, which expressed the essence of 

human life - meaning a blind purposeless will permeating all existence (Russell, 1945). 

Among the pragmatists, Charles Sanders Peirce and William James, the mind evolved as 

an instrument for practical adjustment and not as an organ for the rational plumbing of 

metaphysics. For them, ideas are not to be assessed in terms of logic but in terms of their 

practical results when put to the test of action. 
 

Irrationalism is also expressed in the historicism and relativism of Wilhelm Dilthey, who 

saw all knowledge as conditioned by one‘s private historical perspective and who thus 

urged  the  importance  of  the  ―Geisteswussenschaften‖  (the  humanities)  (2002).  Another 

irrationalist, Johann Georg Hamann, claims that truth could be found in feeling, faith, 

experience and personal conviction, above mere speculation. Friedrich Heinrich Jacobi 

exalted the certitude and clarity of faith to the detriment of intellectual knowledge and 

sensation (Perry, 1992). The likes of Friedrich Schelling and Henri Bergson who were also 

preoccupied with the uniqueness of human experience, relied on the idea of intuitionism, 

―which sees things invisible to science.‖ In fact, they did not attack reason itself, the belief 



Aquino Journal of Philosophy, Vol. 1(1), 

 

was that it had lost its commanding role in as much as personal insights are not to be 

tested. Bergson‘s philosophy and as well as that of Nietzsche, was a form of vitalism and 

as well irrationalistic in holding that instinctive, or Dionysian drive lies at the heart of 

existence (Russell, 1945). 
 

Friedrich Nietzsche saw moral codes as mere myths, lies and frauds created to mask forces 

operating beneath the surface to influence thought and behavior. Nietzsche professed that 

humans are free to formulate new values by claiming that God is dead (Nietzsche, 2002). 

Another thinker, Ludwig Klages extended life philosophy in Germany by urging that the 

irrational springs of human life are ―natural‖ and should be followed in a deliberate effort to 

root out the adventitious reason; while Oswald Spengler extended it to history, which he 

viewed intuitively as an irrational process of organic growth and decay (Stumpf, 2003). 
 

In existentialism, Soren Kierkegaard, Jean-Paul Sartre, and Albert Camus all frowned at 

making sense out of an incoherent world; and each chose his own alternative to reason- 

the leap of faith, radical freedom, and heroic revolt, respectively (Barret, 1962). Generally, 

irrationalism implies either that the world is devoid of rational structure, meaning, and 

purpose; or that reason is inherently defective and incapable of knowing the universe 

without distortion; or that recourse to objective standards is futile; or that in human nature 

itself the dominant dimensions are irrational. 

 

4. Nietzsche and the Irrationalist Movement 

Friedrich  Nietzsche  was  the  principal  figure  in  the  ―dethronement  of  reason‖  and  the 

glorification of the irrational. For him, life abounds in cruelty, injustice, uncertainty, and 

absurdity and this is a fact man must understand in order to enjoy full existence. Nietzsche 

holds firmly that life is not governed by rational principles, there is no absolute standard  

of good and evil, no timeless principles, whose truth can be demonstrated or proven by the 

activity of reflective reason. The idea of a transcendental world or what could be called the 

higher world of metaphysics and even the Christian heaven is for him, a myth. Nietzsche 

claims that nothing is true, all what is available to man is his naked self (naked man)  

living in a godless, chaotic, meaningless, and absurd world. This is the reality, which no 

one but the strong must face, for the weak have no will to face it, and thus invent fables 

about a higher reality and a future life, such as is provided by the Christian faith 

(Nietzsche, 1924). 
 

In fact, Nietzsche claims that modern civilized, mechanized or bourgeois society was 

decadent and enfeebled, it is a victim of excessive development of the rational faculties at 

the detriment or expense of will and instinct. Against the liberal-rationalist stress on the 

intellect, Nietzsche urged the recognition of the dark mysterious world of instinctual 

desires, which for him, are the true forces behind human life. He affirms that what the 

modern bourgeois society has succeeded in achieving was to smother the will with 



Adesanya Reviewing Modern Scientific Knowledge … 

 

excessive intellectualizing, the result of which is the destruction of the freedom or 

spontaneity that sparks cultural creativity and ignites a zest for living. The critical and 

theoretical outlook of the modern time has for too long stifled the creative instincts that 

are the real forces behind human life. Therefore, for man to realize his manifold potential, 

he must stop relying on the intellect and begin to nurture the instinctual roots of human 

existence. This, he expresses as follows: ―I have kept a close eye on the philosophers and 

read between their lines for long enough to say to myself: the greatest part of conscious 

thought must still be attributed to instinctive activity, and this is even the case for 

philosophical thought‖(Nietzsche, 2002). 
 

Traditionally, the Ancient Greek culture has been lauded for its rationality, for originating 

scientific and philosophical thought and for endeavoring to achieve balance, harmony, and 

moderation both in the arts and in ethics. This Ancient Greek culture with its 

overwhelming rationalistic thought system was given an unconventional interpretation by 

Nietzsche. Nietzsche chose to emphasize the emotional roots of Greek culture with 

recourse  to  the  Ancient  Dionysian  spirit  ―that  springs  from  the  soil  of  myth  and  ritual, 

passion and frenzy, instinct and intuition, heroism and suffering.‖ For him, this Dionysian 

spirit, rooted in the non-rational, was the source of and the force behind Greek creativity 

in art and drama. This is what Nietzsche means by the Greek tragedy, which declined 

when serenity, clarity, order, structure, form, and cold calculation – the Apollonian spirit- 

predominated over noble ecstasy and creative intuition. Greek tragedy, for Nietzsche was 

killed by rationalism which is life-undermining. 
 

The rise of modern theoretical outlook of scientific thought which seeks to separate truth 

from myth, illusion, and error, Nietzsche attributes to Socrates. For him, this scientific 

outlook which began with Socrates and attained its height in the Hellenistic age during the 

time of Alexandria, had the basis and set the foundation for modern culture. Nietzsche 

claims that the modern westerner values the theoretical man and not the man of instinct 

and action! As such, they do not appreciate the creative potential and non-rational 

(irrational) side of human nature. Nietzsche then claims that we are beginning to  

recognize and discover the limitations of science and the cognitive faculty itself or 

rationality. Nietzsche talks about Immanuel Kant who has already giving reasons for us to 

doubt the capacity of the cognitive and rational apparatus to apprehend reality in itself, 

and then science‘s claim to the attainment of certainty. For Kant, the senses or the human 

rational and perceptual apparatus are incapable of apprehending things as they are in 

themselves. 

 

5. Nietzsche as the Initiator of Post-modern Thought-system 

Postmodernism represents a united force of diverse intellectual currents with a unanimous 

desire to undermine all categories of thought and assumptions that are typical of the 

historical epoch of Modernism. All attempts to seek universal standards of truth, beauty 



Aquino Journal of Philosophy, Vol. 1(1), 

 

and goodness are seen as not only futile but also restricting and tyrannizing. In place of the 

quest of certainty and validity common with modernism, postmodernist thinkers advocate 

the recognition of infinite differences and acceptance of uncertainty with regards to all 

knowledge. Friedrich Nietzsche is the philosopher who can be said to have ushered-in 

postmodernist orientation in philosophical history. Nietzsche objects to all forms of 

system-building, universal standards of truth and morality. According to him: 
 

There are still harmless self-observers who believe in the 

existence of ―immediate certainties,‖ such as ―I think,‖ or the ―I 

will‖ that was Schopenhauer‘s superstition: just as if knowledge 

had been given an object here to seize, stark naked, as a ―thing-

in-itself,‖ and no falsification took place from either the  side  of  

the  object.  But  I  will  say  this  a  hundred times: 

―immediate certainty,‖ like ―absolute certainty‖ and the ―thing in 

itself‖ contains a contradictio in adjecto (contradiction in 

terms). For once and for all, we should free ourselves from the 

seduction of words!(Nietzsche, 2002). 
 

Nietzsche criticizes Descartes‘ idea of the thinking self (ego) as being the basis for all 

human knowledge, while also repudiating the Kantian idea of the ―thing in itself‖, which 

expresses some sort of objective knowledge that is to be sought after (Nietzsche, 2002). 

For him, there is no immediate certainty that requires only the aid of reason to be grasped 

(just as we have it in Descartes). Any form of system-building presupposes lack of 

integrity. The rejection of absolute truth, objective knowledge, universal morality, and all 

forms of formalisms, brings us to the concept of nihilism in Nietzsche‘s philosophy. 

 

6. Nihilism and Irrationalism in Nietzsche’s Philosophy: A Challenge to Modern 

Science 

As being hinted earlier in this paper, modern scientific thinking emphasizes the rational 

faculty of human cognition as being essential to the production of scientific knowledge, 

while  disregarding  other  elements  of  human  cognition,  such  as  the  ―will‖,  instincts  and 

impulses, as being unable to produce reliable and genuine knowledge. Modern science is 

often projected to possess a rational image, which places emphasis on a fixed, 

universalisable and objective method of inquiry, devoid of uncritical presuppositions 

which are considered as products of irrational cognitive apparatuses of man, such as the 

―will‖.  However,  Friedrich  Nietzsche  proposes  an  opposing  view  which  contrasts  the 

rational outlook of science, as being evident in his nihilistic and irrational reflections. 
 

Nihilism is the extreme view that there is no justification for values. Nietzsche was an 

ardent critic of commonplace ways of thinking about truth and knowledge, for him, all 

thinking is perspectival, there are no facts, all what we have are mere interpretations 



Adesanya Reviewing Modern Scientific Knowledge … 

 

(Nietzsche, 2002). This explains why he was interpreted as rejecting the idea of truth and 

knowledge altogether, and was considered as a radical epistemological and moral nihilist. 

Yet, it can be said of Nietzsche, that he manifested a passionate commitment to 

truthfulness, and made philosophical postulations which he himself supposed to have 

something like knowledge as their aim. ―Zarathustra‖ speaks thus: 
 

I appeal to you, my brothers, remain true to the earth, and do 

not believe those who speak to you of otherworldly hopes! 

Poisoners are they, whether they know it or not. Despisers of 

life are they, decaying and poisoned themselves, of whom the 

earth is weary: so let them pass away! Once sin against God 

was the greatest sin; but God died, and with him these sinners. 

To sin against the earth is now the most terrible sin, and to 

revere the entrails of the unknowable higher than the meaning 

of the earth!(Nietzsche, 2010), p. 13-14. 
 

Nietzsche considers those things which are beneath the human nature, such as intuition, 

blind strivings, emotions, feelings, impulses, as providing the most reliable source of 

understanding and knowledge that is required to achieve a fuller existence. In proclaiming 

the death of God, he expresses the demise of universal morality, while proposing 

something radical, like self-acclaimed values. Nietzsche conceives human thoughts and 

actions as being constrained by values and at the same time clears the way for a new set of 

values which are constituent with human needs. Systems of values, as well as all 

knowledge, are for him, a set of illusions. 
 

However, the implications of Nietzsche‘s irrationalist views for the enterprise of modern 

science is that the underlying assumptions that are often devised in support the rational 

image of science are mostly misguided. The assumptions often used in support of the 

rational image of science include the views that scientific knowledge is the only form of 

reliable knowledge available to man, that science is the paradigm of rationality, that 

science is the sole model of truth, that science is entirely based on facts, that only reason 

can guide man to the apprehension of reliable knowledge and a plethora of others. All 

these underlying assumptions of modern scientific rationality are being faulted and 

‗mocked‘ by Friedrich Nietzsche, who upholds the contention that genuine knowledge can 

only be derived from the more creative elements of human nature which are more indebt 

in man, such as the will, creative instincts, impulses, animalistic outbursts, and dark 

strivings (Nietzsche, 2010). As fallout of Nietzsche‘s irrationalist doctrines is the 

contention that the enterprise of science can be more comprehensive in terms of approach 

and method by acknowledging and adopting the irrational sources of human knowledge. 



Aquino Journal of Philosophy, Vol. 1(1), 

 

It is therefore on the basis of the above analysis of the challenge posed by Nietzsche‘s 

irrationalism to the enterprise of modern science that it is proposed in this paper that the 

assumption that science is based on fact and objective knowledge presupposes that the 

enterprise of science is methodologically handicapped, as it can only come to terms with 

the rational aspects of human cognition, while disregarding the efficacy of the irrational 

elements of man in the production of reliable knowledge. It will be of immense benefit to 

the enterprise of science if other non-rational sources of knowledge can be investigated 

and adopted veritable sources of reliable and scientific knowledge. Moreover, the very 

idea of fact, which science claims to explain is under contention, due to the several 

numerous interpretations given to the idea in different cultural and methodological 

contexts (Chalmers, 1999). 

 

7. Conclusion 

The basic assumptions that underlie scientific rationalism and the philosophical 

irrationalism of Friedrich Nietzsche have been extensively discussed in this paper, while 

also delving into a general analysis of the idea of philosophical irrationalism as a doctrine 

that upholds the irrational elements and sources of knowledge and human cognition, such 

as will, instincts, impulses and emotions. The scientific enterprise has been portrayed in 

this research work as a rational and objective enterprise, which bases its approach and 

methods on the principles of rationality. However, having given thorough considerations 

to Nietzsche‘s contentions about the misguided assumptions underlying the rational image 

of science, which include the views that science is not the paradigm of rationality, that 

reason alone cannot serve as the only reliable source of knowledge, and that the irrational 

elements of human cognition are more efficacious in the apprehension of reliable 

knowledge; the paper thereby submits that the enterprise of modern science can be more 

comprehensive in terms of approach and method by incorporating the irrational sources of 

knowledge in its research programs. Moreover, Friedrich Nietzsche has been discussed in 

this paper as being the harbinger of the post-modernist thought system, owing to his 

critique of all forms of system-building, universal standards and principles of rationality, 

and grand-theorizing. 



Adesanya Reviewing Modern Scientific Knowledge … 

 

 
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