Frege's Philosophy of Language

Posted by Ali Reda | Posted in | Posted on 2/25/2016

While pursuing his investigations into mathematics and logic, in order to ground those investigations, Frege was led to develop a philosophy of language. Frege considered two puzzles about language and noticed, in each case, that one cannot account for the meaningfulness or logical behavior of certain sentences simply on the basis of the denotation (reference) of the terms (names and descriptions) in the sentence. One puzzle concerned identity statements and the other concerned sentences with subordinate clauses such as propositional attitude reports. To solve these puzzles, Frege suggested that the terms of a language have both a sense and a denotation (reference).

First Puzzle

The statement ‘a=a’ has a cognitive significance (or meaning) that is different from the cognitive significance of ‘a=b’. We can learn that ‘Mark Twain=Mark Twain’ is true simply by inspecting it (knowable a priori); but we can't learn the truth of ‘Mark Twain=Samuel Clemens’ simply by inspecting it, we have to examine the world to see whether the two persons are the same (discovered a posteriori). So the puzzle Frege discovered is: how do we account for the difference in cognitive significance between ‘a=b’ and ‘a=a’ when they are true? And why ‘Mark Twain=Samuel Clemens’ seems informative?

Second Puzzle

When we report the propositional attitudes of others, these reports all have a similar logical form:
x believes that p
x desires that p
x intends that p
x discovered that p
x knows that p

If John believes that Mark Twain wrote Huckleberry Finn. And Mark Twain=Samuel Clemens, therefore, John believes that Samuel Clemens wrote Huckleberry Finn. But this argument is not valid. There are circumstances in which the premises are true and the conclusion false. John may not believe that Samuel Clemens wrote Huckleberry Finn. The premises of the above argument, therefore, do not logically entail the conclusion. So the Principle of Identity Substitution appears to break down in the context of propositional attitude reports. This law was stated by Leibniz as, "those things are the same of which one can be substituted for another without loss of truth," a sentiment with which Frege was in full agreement. As Frege understands this, it means that if two expressions have the same reference, they should be able to replace each other within any proposition without changing the truth-value of that proposition. Normally, this poses no problem. However, it is not always true that they can replace one another without changing the truth of a sentence. The puzzle, then, is to say what causes the principle to fail in these contexts. Why aren't we still saying something true about the man in question if all we have done is changed the name by which we refer to him?

Frege's Solution

Frege suggested that in addition to having a denotation (reference), names and descriptions also express a sense. The sense of an expression accounts for its cognitive significance, it is the way by which one conceives of the denotation (reference) of the term. The expressions ‘4’ and ‘8/2’ have the same denotation (reference) but express different senses, different ways of conceiving the same number. The descriptions ‘the morning star’ and ‘the evening star’ denote the same planet, namely Venus, but express different ways of conceiving of Venus and so have different senses. The name ‘Pegasus’ and the description ‘the most powerful Greek god’ both have a sense (and their senses are distinct), but neither has a denotation (reference). However, because the senses of these expressions are different--in the first sentence, the object is presented the same way twice, and in the second, it is presented in two different ways, it is informative to learn of the second statement.

Using the distinction between sense and denotation (reference), Frege can account for the difference in cognitive significance between identity statements of the form ‘a=a’ and those of the form ‘a=b’. Since the sense of ‘a’ differs from the sense of ‘b’, the components of the sense of ‘a=a’ and the sense of ‘a=b’ are different. Frege can claim that the sense of the whole expression is different in the two cases. Since the sense of an expression accounts for its cognitive significance, Frege has an explanation of the difference in cognitive significance between ‘a=a’ and ‘a=b’, and thus a solution to the first puzzle.

Moreover, Frege proposed that when a term (name or description) follows a propositional attitude verb, it no longer denotes what it ordinarily denotes. Instead, in such contexts, a term denotes its ordinary sense. This explains why the Principle of Identity Substitution fails for terms following the propositional attitude verbs in propositional attitude reports. The Principle asserts that truth is preserved when we substitute one name for another having the same denotation (reference). But, according to Frege's theory, the names ‘Mark Twain’ and ‘Samuel Clemens’ denote different senses when they occur in the following sentences:

John believes that Mark Twain wrote Huckleberry Finn.
John believes that Samuel Clemens wrote Huckleberry Finn.

If they don't denote the same object, then there is no reason to think that substitution of one name for another would preserve truth.

Sense of a Sentence

The reference of the whole proposition depends on the references of the parts and the sense of the proposition depends of the senses of the parts. Frege even suggests that the sense of a whole proposition is composed of the senses of the component expressions. Frege calls the sense of a sentence a thought, he supposes that there are an infinite number of thoughts and the denotation (reference) of a sentence is one of the two truth values.

On Frege's view, the sentences ‘4=8/2’ and ‘4=4’ both denote the same truth value. The function ( )=( ) maps 4 and 8/2 to The True, i.e., maps 4 and 4 to The True. So d[4=8/2] is identical to d[4=4]; they are both The True. However, the two sentences in question express different thoughts. That is because s[4] is different from s[8/2]. So the thought s[4=8/2] is distinct from the thought s[4=4]. Similarly, ‘Mark Twain=Mark Twain’ and ‘Mark Twain=Samuel Clemens’ denote the same truth value. However, given that s[Mark Twain] is distinct from s[Samuel Clemens], Frege would claim that the thought s[Mark Twain=Mark Twain] is distinct from the thought s[Mark Twain=Samuel Clemens].
Furthermore, recall that Frege proposed that terms following propositional attitude verbs don’t denote their ordinary denotation (reference)s but rather the senses they ordinarily express. For example:

John believes that Mark Twain wrote Huckleberry Finn.
John believes that Samuel Clemens wrote Huckleberry Finn.

Not only do the words ‘Mark Twain’, ‘wrote’ and ‘Huckleberry Finn’ denote their ordinary senses, but also the entire sub-sentence ‘Mark Twain wrote Huckleberry Finn’ also denotes its ordinary sense (namely, a thought). And since the thought denoted by ‘Samuel Clemens wrote Huckleberry Finn’ in this context differs from the thought denoted by ‘Mark Twain wrote Huckleberry Finn’.

Frege's analysis therefore preserves our intuition that John can believe that Mark Twain wrote Huckleberry Finn without believing that Samuel Clemens did. It also preserves the Principle of Identity Substitution—the fact that one cannot substitute ‘Samuel Clemens’ for ‘Mark Twain’ when these names occur after propositional attitude verbs does not constitute evidence against the Principle.

The Theory of Beauty in the Classical Aesthetics of Japan

Posted by Ali Reda | Posted in | Posted on 11/20/2015

To the yearning seekers of blossoms
With pride, would I offer
A delight of the eye,
The green from under the snow
In a mountain village in springtide!

The 'mystery' of Japanese aesthetics comes from the fact that there is a peculiar kind of metaphysics, based on a realization of the simultaneous semantic articulation of consciousness and the external reality, structurally comprising within itself, as an organic whole, the metaphysical, ethical, and aesthetic experiences of the Japanese, dominating the whole functional domain of the Japanese sense of beauty.

It tries to create an associative network of semantic articulations, i.e. a non-temporal 'space' of semantic saturation, bringing into being a global view of a whole (a "field"), in which the words used are observable all at once which is impossible except within the framework of an extremely short poem like waka (31 syllables) and haiku (17 syllables). In a "field" thus constituted, time may be said to be standing still or even annihilated in the sense that the meanings of all words are simultaneously present in one single sphere. Instead of a linear, temporal succession of words, in which each succeeding word goes on obliterating, as it were, the foregoing word.

There are two most important points to be remarked about this spatial, non-temporal image of reality. The first is that, unlike in the reality imaged as the empirical field of causal sequence, there is not supposed to be any priority-posteriority relationship between the things and events which arise therein. Nor should there be any pivotal centers seen around which the things and events would coagulate and tum and at which the relational continuum of co-existence would terminate. That which sustains this image of reality is an awareness of diversity and manifoldness in the form of accidental coincidences, accidental correlations, correspondences and contrasts among things converging into a universal existence with its inner metaphysical dynamics, rather than the awareness of their temporal-causal sequence. In such a perspective, even what is ordinarily considered temporality would appear in a completely different light, for it would then appear identified simply as a perpetual 'inconsistency-transiency' (mu-jo).

As an aesthetic idea it is a feeling of aesthetic harmony fermented in and induced from contemplative awareness. This inner harmony, first projected onto the empirical dimension of things and events. The human reality in this sense may be structurally represented as a sort of existential 'field' that is actualized between the subject and object as its two poles. It would only be natural that the 'field' constituted in this way should have validity only for human existence. To express the same thing from its reverse side, human existence emerges and disappears together with the 'field', that is, human existence cannot maintain itself apart from the 'field'. Or we must say rather that human existence consists precisely in the act of constantly and ceaselessly producing the 'field'. Consequently it would be a sheer impossibility for man to go over the limits of this 'field' and step out of it while remaining at the same time a human being.

The first level of the contemplative 'field' comes into being when the cognitive focus of the subject-which ordinarily is directed toward the outer world unilaterally and one pointedly-begins as it were gradually to become enlarged and diffused until it transcends itself in the sense that it turns into a synchronically multiple awareness directed toward the entire 'field', which is replete with a particular dynamic tension arising from the very co-existence of all things in the all-comprising focal point of such an awareness in one single nontemporal dimension.

At the second level of the contemplative 'field', there no longer exists the vivacious beauty of the phenomenal world. The internal and the external, the subjective and the objective, the perceiver and the perceived, the field and the awareness of the field, the contained and the contaner: whichever of these pairs of opposing units we might posit as the ultimate realms of articulation, we invariably witness primordial poles of reality, almost fused into one another, leaving, however, their faint traces of articulate boundaries, constituting between them a harmonious equilibrium, like a silver bowl and snow heaped therein reflecting each other in an illuminating saturation of silvery light. Such is the whole reality and such is also the whole width of consciousness, and between the two is maintained a state of perfect equilibrium. There is nothing else. This is the whole that IS.

The transition from the second to the third level of the contemplative 'field' may figuratively be represented as a process by which an image of a physically visible extension gradually changes into an image of unfathomable depth. At this stage, hqwever, the never-reconcilable polarity between 'being' and 'not-being' loses its validity as a rationally immutable law. Here, for the first time, is opened a transcendental realm which makes it possible for an ambivalence between these two, 'being' and 'not-being', to be realized. All that have been articulated in recognizable forms fall into the depths of the darkness of night.

But once we reach the fourth level, we witness something beyond imagination. Quite contradictorily, the unfathomable darkness itself becomes suddenly transformed into a boundless dazzling light. However, this abysmal darkness can be at the same time the brilliance of the sunlight. The darkness and brilliance in this case are freely transmutable into one another, because neither of them is an outcome of the articulating activity of the mind. They are rather two forms of the self-manifestation of the primordial Nothingness, the non-articulated, comprising in itself all possible things. The 'mysterious singularity' is beyond the reach of all verbal expressions and indeed absolutely transcends all the activities of the human mind.

On the basis of the awareness of the essential structure of human existence, one may still cherish the intention to transcend its inherent limitations and go beyond them. Such is the nature and motivation of the Japanese form of contemplation. The same idea may also be expressed in a different way by saying that the supreme objective of contemplation consists in man's making an unremitting effort to intend, and approach as closely as possible, the undetermined whole, the nonarticulated Reality which lies beyond human existential reality. Even if by this effort he is able to catch only a brief and passing glimpse of a very narrowly limited aspect of the non-articulated, the attempt is still made. These poets and artists gaze intently at the invisible beyond the visible. They exert themselves to go beyond their sensuous limitations.

In the traditional terminology of Japanese thought, the nonarticulated is called Nothingness (mu), while the articulated is called 'being' (yil or u). In the metaphysical view of the Japanese, it is this very Nothingness as the non-articulated whole that is to be considered the sole Reality. The articulated is thus none other than the dimension of 'being' as the empirical field of life produced by the activity of the 'existential' articulation of human consciousness. This dimension of 'being' which has emerged out of Nothingness as its ground, is brought back to the vision of the original Nothingness through contemplative experience, dissolving its own phenomenal coagulations that have been produced by articulation. The inner strcuture of the aesthetics which we have analyzed so far is, as has been seen, based on a metaphysics having Nothingness as its ultimate goal to be reached, by actually realizing an exquisite organic whole of spatial equilibrium in its serene timelessness.


In waka it is usually the case that self-expression is almost necessarily interwoven with Nature-description. In fact waka could be defined as a self-expression through Nature-description. The inner domain of semantic associations linked with, and substantiated by, the associations of empirically articulated things in external Nature as related to human existential experiences. Thus Nature, actually envisaged by the poet, constitutes in itself a kind of Nature-'field' where the inner existential phenomenal activity of his Subjectivity, his inner 'field' of contemplative Awareness, finds its proper locus for externalization, where he can get into the most immediate and intimate contact with his own inner Self (the non-articulated).

As a result, the units of semantic association actualized in waka assume an evocative significance against the background of this vast, universal totality of the associative networks of Nature interlinked with human affairs. We may observe furthermore the peculiar fact that the associative network of natural things and events shows a remarkable tendency to go on dilating itself into the vastness of rarefied infinity. Consequently we hardly find a waka-poem, a tiny linguistic 'field' of 31 syllables as it is, devoid of a feeling of the cosmic amplitude of Nature, whether its main subject be love or grief.


Yugen, the first component of the word yugen, usually connotes faintness or shadowy-ness, in the sense that it rather negates the selfsubsistent empirical solidity of existence, or that it suggests insubstantiality. Gen, the second component of the word, means dimness, darkness or blackness. It is the darkness caused by profoundity; so deep that our physical eyesight cannot possibly reach its depth, that is to say, the darkness in the region of unknowable profoundity. It may be sufficiently clear from what has just been said that yugen is not a mere aesthetic idea but rather a complex one closely and fundamentally related to the awareness of existence. For we observe in it an inherent tendency which, if developed, would almost exclusively be directed toward a metaphysical awareness.

The beauty of yugen is faint, delicate, suggestive because it is based on the awareness of insubstantiality and delimitation of the human existential field. It is a beauty of spiritual aspiration and yearning motivated by the desire to have sensuous images of the non-articulated, non-sensuous reality of eternal silence and enigma in the midst of the phenomenal world. As we sometimes experience, even the empirical world in which we live, observing things and events coming into and going out of existence, becomes transformed before our eyes into a field, intangible and mysterious, in which things and events assume a tinge of yugen, losing the empirical solidity of self-subsistency, wafting as it were in the air, thus pointing to the presence of the primordial, non-articulated reality underlying them.


The beauty of Nature as a positive aesthetic value, they thought, was not to be appreciated at the momentary height of its full actualization so much as in its transient process of subsiding, or even in its vestiges left after its nullification.

The idea of wabi thus metaphysically understood seems to show quite an obvious characteristic in its structure. It refers first of all to a peculiar metaphysical or existential region which is to be located as it were somewhere between the phenomenal and pre-phenomenal or the articulated and non-articulated whole. This structure observed in its dynamics of involvement and evolvement to and from Nothingness is the sole fundamental basis of the aesthetic idea of wabi.

The phenomenal things and events when viewed in terms of wabi, i.e. a particular metaphysics of Nothingess, naturally come to show quite a characteristic inner configuration as a temporal reflexion of the inner dynamics of the non-temporal structure of Nothingness. That is to say, the process of inner dynamics of evolvement and involvement finds its analogy in the phenomenal movement and changes which, though outwardly indistinct and invisible, are going on steadily, leaving their traces accumulated in the depths of the phenomenal things, as may be visualized by the example of a growth ring of a tree.


In the world of haiku, Nature (and also human affairs) is not simply perceived, recognized and described. It must be 'grasped' on the spot by the poet in its dynamic momentum and immediate experiential actuality, as a phenomenal drama in which the existential whole of the creative-cognitive subject encounters the external world dialecticly. Each event of the subject-object encounter takes place once and for all, lasts only for a moment, ends once and for all, and 'disappears, leaving no trace behind', into Nothingness, the non-phenomenal, non-articulated whole. In each of the actual occurrences of dialectic encounter there are realized illuminating correspondences between the subject and object in their phenomenality. Both the creative-cognitive subject and the cognized object disclose their own phenomenal aspects to each other moment by moment in their limitless varieties and variegations. A certain phenomenal aspect ofthe creativecognitive subject illumines outward a certain particular aspect of the cognized object, which in its turn steers the self-illuminating focus upon another particular aspect of the cognitive subject itself, thus continuing indefinitely, and each phase of this illuminating correspondence forms the potential poetic 'field' of the event itself. The cognitive subject and the cognized object are merely the two poles constitutive of the energy 'field' of the phenomenal, existential event, which the linguistic 'field' of haiku tries to represent with its centripetal dynamics.

In the creative actuality of haiku, there should not be any interval even by a hair's breadth between the state of mind and the cognitive perceptual act. The first and faintest stir of the inner reality (bi) emerges from the thing, it activates the creative emotion of the poet (as an instantaneous sensation), which becomes crystallized on the spot into a poetic expression. There is a remark by the Master concerning the composition of verses: 'Crystallize the first flash of things perceived into words while your mind remains still illumined by its reminiscence.' In other words, the state of mind is most immediately connected with the cognitive act of perception itself with absolutely no intervention of inner activity of semantic articulation, resulting in the immediate descriptive expression of it, thus completing the whole process of the creative-cognitive 'event' of haiku. Thus what he describes or expresses should be superbly natural, with no arbitrary intricacy in itself. As the late Master once remarked: 'In the art of haiku a poem should always be composed in tune with the creative momentum'. He should, leaving at this stage no longer even a trace of doubt and vacillation in his mind, express instantaneously and with immediacy things that occur to his mind, without allowing, so to speak, any discrepancy even as a hair's breadth between his inner self and the writing desk, with a spirit comparable to that of "felling a giant tree down to the ground".

The old pond,
A frog flops in,
The water sound.

The faint sound of water which in itself has not even a trifle aesthetic meaning or which aesthetically makes no sense, by being recognized by the cognitive-creative subject. It is in this sense that in haiku the state of mind is linked immediately and directly with sensation and sense perception while in waka it is the inner activity of semantic articulation which is incorrigibly associated with the state of mind. The plainness, mundaneness or even vulgarity of haiku-expression- in contrast to the sophistication of the aesthetic idealism of waka-assumes an important significance only in this structural framework of haiku as an existential-aesthetic experience. What is implied thereby is that in this particular case the nonphenomenal Whole, the unknowable, is not to be found in the horizontal extension of the semantic articulation, and it is ontologically posited in an entirely different dimension. Accordingly its presence is only indicated by the very absence of phenomenal articulation. What is actualized 'here and now'. This inner state which is beyond the reach of all verbal expression, and in which there is no room for cogitation, and indeed which transcends all the activities of human mind-that precisely is the state of'myo' (the mysterious singularity). Myo (mysteriously singular) refers to a state beyond words, where the activity of the mind utterly disappears without a trace. The artistic state now transcends and is perfectly free from all fixed value-ideas, such as right-and-wrong and good-and bad in the ordinary sense of the words.

The Code of the Samurai: A Modern Translation of the Bushido Shoshinshu of Taira Shigesuke

Posted by Ali Reda | Posted in | Posted on 11/10/2015

One who is supposed to be a warrior considers it his foremost concern to keep death in mind at all times, every day and every night, from the morning of New Year’s Day through the night of New Year’s Eve.

As long as you keep death in mind at all times, and realize that the life that is here today is not certain on the morrow, for a knight, life is here today, uncertain tomorrow. Therefore he realizes everyday that he has this one day to serve, so he does not become bored or neglect any of his duties. Then when you take your orders from your employer, and when you look in on your parents, you will have the sense that this may be the last time-so you cannot fail to become truly attentive to your employer and your parents. This is why I say you also fulfill the paths of loyalty and familial duty when you keep death in mind.

In contrast to this, when you think you will be on the job forever, then trouble starts. You get bored, so you become inattentive and lazy. If people comfort their minds with the assumption that they will live a long time, something might happen, because they think they will have forever to do their work and look after their parents-they may fail to perform for their employers and also treat their parents thoughtlessly. Since no one takes personal responsibility for taking care of them, tasks pile up and there is nothing but snafus. These are all mistakes that come from counting on having time in the future.

The process of cultivating the practice of doing right begins with fear of being disrespected by those close to you, starting with your family and servants, then advances to refraining from doing wrong and deliberately doing right for fear of incurring the shame of being censured and ridiculed by society at large. Anywhere forbidden by the regulations of his employment, or disliked by his parents, he will avoid going even if he wants to. He will give up even those things that are hard to give up, just to avoid displeasing his employer and parents.

While it goes without  saying that an attitude of hardness and strength is considered foremost in the way of the warrior, if strength is all you have you will seem like a peasant turned samurai, and that will never do. You should acquire education as a matter of course, and it is desirable to learn things such as poetry and the tea ceremony, little by little, in your spare time. If you have no education, there is no way for you to understand the reasons of things past or present. Then no matter how smart or cunning you may be, in actual practice dealing with events you will run into many obstacles.

How to deal with a knight who is corrupting your overlord

Now even if the whole establishment hated the knight in question, who makes up the tax rolls, denouncing him as a devil in the house and an enemy of the overlord, with nine out of ten testifying to his iniquities, seeing no alternative but to take the matter to court and argue their case verbally with-out dirtying their hands, the problem would hardly be resolved privately—the overlord's whole organization could be investigated by the central government, and if things grew worse it could become a public scandal and a cause for government action. Throughout history, there has never been a case where a baron who was unable to manage his establishment and therefore had to resort to the central government actually had the matter resolved that way and maintained his own position. Just as in the metaphors of killing an ox to straighten its horns, or burning down a shrine to catch a mouse, when the overlord loses his position the personnel of the whole establishment, major and minor, are all disenfranchised.

In this case, the logical thing to do is to seize the villain, that devil of the house, that enemy of the overlord, and do away with him as you will—run him through, or strike off his head—and then when that is done satisfactorily you immediately disembowel yourself, committing suicide. Then there will be no government inquiry, and the overlord's position will not be affected. Thus the personnel of the establishment will be secure, and the country will be peaceful. In this way you become a role model for knights of latter days—loyal, dutiful, and courageous—a hundred times better than one who kills himself to follow his overlord in death.

Virtual Box Images Deployment

Posted by Ali Reda | Posted in | Posted on 10/07/2015

zip files and ovf file

Select File->Import Appliance and choose SampleAppv207_OBI_11. file. Select ‘Next’. In Appliance Import Settings screen, go to the Virtual Disk Image property. Change the path to a desirable location where you’d like to create the deployed disk image files and click on Finish. It might take about 45 mins to import. After completing import, you may delete the unzipped .ovf and .vmdk files because you have created the new vbox and vmdk files.

vdi(ORACLE Virtual Box) or vmdk(VMWARE) disc image files

Select New -> Oracle Linux (64-bit) -> use existing Harddisk and spicfy the vdi or vmdk image file location, Once finished you can't delete the vdi or the vmdk file because you need it as you have created only vbox file.

Note: Oracle VM VirtualBox can open VMware native virtual machine hard drive files in .vmdk format. But VMware can't open VirtualBox .vdi files.

توماس كون ضد بوبر

Posted by Ali Reda | Posted in | Posted on 9/10/2015

يعتبر توماس كون واحد من أهم فلاسفة العلم الذى ينادى بنظرية مختلفة تماما عن بوبر فيلسوف العلم الأشهر فى تفسير التقدم العلمى. وربما يرجع ذلك لأن كون هو من أعمدة "اللا واقعية" على العكس من بوبر "الواقعى". تنادى المدرسة الواقعية بأن العلم ما هو إكتشافات متتالية للحقيقة المطلقة فى كوننا وتلك الحقيقة مطلقة بمعنى أنها واحدة لأى عالم يتأمل فى الكون. وبالتالى فالعلم هو إكتشاف وليس إختراع، وأستكمل بوبر هذا الخط فى إعتبار أن أى شذوذ فى الملاحظات أو النتائج العلمية لا تستطيع النظرية الحالية تفسيره، يجعل النظرية خاطئة وفى حاجة للتصحيح الفورى بتغيير النظرية كلها أو على الأقل تغيير فرضية من فرضياتها وبإستمرار تلك السلسلة من التخطئة (Falsification) والتغيير، نقترب تدريحيا من الحقيقة المطلقة فى الكون وهو ما يسميه بوبر بأن لعبة العلم مفتوحة دائما. ويمكن تلخيص موقف بوبر من النظريات العلمية، أنه يفترض دائما أن النظرية العلمية خاطئة من الأساس حتى يتم إثبات ذلك وتغييرها بالنظرية الأفضل. ومن أهم نتائج هذه الأطروحة، أن أعتبر بوبر لغة العلم واحدة، فالمصطلحات التى تستعملها ميكانيكا نيوتن كالكتلة أو السرعة يمكن مقارنتها بنفس المصطلحات فى النسبية العامة وأن أى تغيير فى التعريف هو أساسا نتاج التغيير فى النظرية للأفضل.

لكن توماس كون يرى العكس من ذلك تماما والذى نشر كتابه  "بنية الثورات العلمية" عام 1962 أى بعد 30 عام من بوبر. فالمدرسة "اللا واقعية" التى ينتمى لها كون، ترى أن العلم إختراع نسبى وليس إكتشاف لحقيقة مطلقة، وبالتالى فالعلم ما هو إلا عدسة يستعملها كل شخص بفهمه وبطريقته الى تختلف من شخص لأخر وبالتالى فالمصطلحات العلمية تختلف من شخص لأخر وبالتالى من صاحب نظرية لصاحب نظرية أخر إذا فلغة العلم ليست واحدة بل تختلف من شخص لأخر أو على الأقل من نظرية لأخرى بل والأخطر أنه وفق تلك النظرة، لا يمكننا من مقارنة نظرية بأخرى بسبب إختلاف لغة العلم بينهما. وفى غياب حقيقة موضوعية مطلقة فى الكون وإبدالها وجهات بنظرات نسبية للعالم وبالتالى فكل النظريات صحيحة وفق نظرتها النسبية للعالم. والجدير بالذكر أن فكرة غياب حقيقة موضوعية مطلقة فى الكون ورؤيته للنظريات العلمية أنها وجهات نظر نسبية، قد جعل المجتمع العلمى يهاجم كون وأطروحته بأنها مهينة للعلم. من السهل أن نلخص تتابع النظريات العلمية فى منهج كون كالتالى:

1) العلم يتكون من مجموعة من الأفكار والإفتراضات التى تنتج نموذج معين (paradigm)، وعند قبول المجتمع العلمى الحالى لهذا النموذج فإن إفتراضاته تعتبر من الثوابت الأرسوذكسية التى من المحرم التشكيك فيها. وأى نجاح لهذا النموذج فى تفسير الكون، يعتبر بمثابة درع له فى نفوس العلماء الذين يكبرون فى وسط هذا النموذج، ضد أى شذوذ فى الملاحظات أو النتائج العلمية، مما يجعلهم يقضون معظم حياتهم العلمية فى إيجاد حلول للشذوذ فى الملاحظات أو النتائج العلمية بتقوية النموذج وتكبيره وويسمى كون هذه العملية "العلم الطبيعى" (Normal Science).

2) تستمر العملية السابقة حتى يظهر شذوذ معين فى الملاحظات أو النتائج العلمية، لا يستطيع النموذج الحالى تفسيره. ولكن حجم هذا الشذوذ يترك تقديره لنفوس العلماء فى المجتمع العلمى، فالعلماء القدامى سيدافعون عن النموذج القديم لأنهم تربوا عليه وعلى إفتراضاته وسيدعون أن الشذوذ كان نتيجة خطأ فى القياس أو أنه سيتم إضافة إفتراض جديد للنظرية يفسر ذلك الشذوذ كما أعتادوا أثناء مرحلة العلم الطبيعى، أما العلماء الشباب فسيسارعون للبحث عن نموذج جديد لتفسير كل ما فسره النموذج القديم بالإضافة إلى تفسير للشذوذ الذى فشل فى تفسيره النموذج القديم.

3) نصل لمرحلة الكارثة (crisis)، عند وجود العديد من الحالات الشاذة والتى لا يستطيع النموذج تفسيرها، فيحدث إن المجتمع العلمى يتقبل التغيير فى صورة النموذج الجديد (paradigm shift)، وعزو كون التغيير لسبيين: إما أن سيطرة العلماء القدامى ضعفت على المجتمع العلمى بسبب الوفيات أو الإحلال والتبديل بالعلماء الشبان أو أن الكارثة كبيرة جدا لدرجة تغيير أن العلماء القدامى مضطرين لتغيير رأيهم. نلاحظ أن كون يتحدث عن أسباب الثورات العلمية كأسباب إجتماعية ونفسية وكصراع بين العلماء القدامى والعلماء الشباب بالأساس مما يتناسب مع نظرته اللا واقعية ونتائجها الإجتماعية.