Aristotle's Conception of Technology

 


Nature and Techne

Aristotle presents basically the same conception of technology as Plato, except for the emphasis on mathematics: technology has a low social and epistemic status and it imitates nature. Nevertheless, Aristotle does not simply repeat Plato but he has a more comprehensive treatment of technology. Aristotle establishes in his Physics that there are four causes for every thing that exist, either naturally or by art: the material cause, the formal cause, the efficient cause, and the final cause. For example, a bronze statue is made out of bronze (material cause), having its particular form (formal cause), it is made by artist's actions with the help of tools (efficient cause), and it serves for religious worship (final cause) (Ross, 2005: 45-47). An important distinction that Aristotle draws is between the cause being in the thing itself and its being external to the thing, i.e. the thing is caused by something else. Technological things are the things that have their causes (the formal, the efficient and the final causes) in men, i.e. the things that are made by the work of men who imprint in matter a form that preexist in man's soul for some human purpose.

The craftsman imprints on matter a certain form that pre-exists in his soul. Aristotle tries to explain where this form comes from. Is it a human invention or is it an imitation of nature? He takes the example of a house and shows that the form of a house comes neither from pure imitation nor from pure invention. In fact, the form of the house is an innovation, a completion of nature's purposes.

Thus if a house, e.g., had been a thing made by nature, it would have been made in the same way as it is now by art; and if things made by nature were made not only by nature but also by art, they would come to be in the same way as by nature. The one, then, is for the sake of the other; and generally art in some cases completes [epiteleitai] what nature cannot bring to a finish, and in others imitates [mimeitai] nature (Physics, 199a).

The form of the house is a natural end; it is a final stage of natural development. The only problem is that nature cannot accomplish by itself its purposes partly because of accident (health is damaged by illness), partly because of complexity (building houses requires too complex operations). Consequently, human technology is a natural way to complete what nature cannot finish. 

The question might be raised, why some things are produced spontaneously as well as by art, e.g. health, while others are not, e.g. a house. The reason is that in some cases the matter which determines the production in the making and producing of any work of art, and in which a part of the product is present, is such as to be set in motion by itself and in some cases is not of this nature, and of the former kind some can move itself in the particular way required, while other matter is incapable of this; for many things can be set in motion by themselves but not in some particular way ... Therefore some things cannot exist apart from some one who has the art of making them, while others can exist without such a person (Metaphysics, 1034a).

This feature, of completing natural purposes, is not particular to human technology, because nature creates nests, spider-webs and other things through the work of animals (birds, spiders, etc.) that do not have rational souls: “This is most obvious in the animals other than man: they make things neither by art nor after inquiry or deliberation. That is why people wonder whether it is by intelligence or by some other faculty that these creatures work,—spiders, ants, and the like” (Physics, 199a)¹. Thus, in cases in which the product of technology does not exist naturally, it is made by following the natural path of development. If the thing exists naturally, the craftsman should faithfully imitate nature. Therefore, technology is a matter of imitating natural things or completing the natural evolution of things without inventing new forms. Technology's end is nature or the aim of technology is to produce things exactly as nature would have produced them. Moreover, to complete nature is more or less the same thing with imitation. If imitation means to do things in the same way they are in nature, to complete nature is to do things in the same way they naturally should be. The technician should always consider the intent of nature. The passage quoted earlier from Physics should be read both as descriptive and as normative. It describes that technology is a imitation, but it also prescribes that technology should be so, and this is indeed how the scholastics understood it. The normative element of the passage rejects the possibility and the desirability of invention. One should not try to modify the technology, except by imitating nature, otherwise he may come to be in conflict with nature. Aristotle rejects technological inventions that are totally new and do not complete the existing potentialities of nature, either because that would impair natural perfection or because it is impossible to create things that do not exist potentially in nature.

Technology needs to imitate nature not only in its final products but also in its ways of proceeding. Tools used in technology are best suited for an operation if they are copies of natural objects: “in the ordinary crafts the best tools were discovered from nature” (Fragments, Dialogues, Iamblichus, Protrepticus 54.10-56.12 Pistelli, B47). The purposive character of technology is an imitation of the purposive character of nature. “If, then, art imitates nature, it is from nature that the arts have derived the characteristic that all their products come into being for the sake of something” (Fragments, Dialogues, Iamblichus, Protrepticus 54.10-56.12 Pistelli, B14). Similarly, the order of technological operations should follow the sequence of natural processes.

Nevertheless, the imitation and the completion of nature do not amount to identity between natural products and technological products. It is true that a house made by art is similar to a house that would have been made by nature. The similarity holds as far as the actual function of a house is concerned. However, a certain property of natural objects, that of self-reproduction is an absolute limit for technology. From the point of view of the natural order, technology has the character of the accident and, like monsters, artefacts are not self-reproducible:

if you planted a bed and the rotting wood acquired the power of sending up a shoot, it would not be a bed that would come up, but wood which shows that the arrangement in accordance with the rules of the art is merely an accidental attribute, whereas the substance is the other, which, further, persists continuously through the process (Physics, 193a)

Technology is external to its products while nature is not. The efficient, final and formal causes of technology lie in the technician that imprints them on matter. This imprinting is only accidental to the imprinted substance and it does not change the real nature of things. Only the material cause (what the thing is made of) is wholly present in the technological product and it retains its own principles of change.

The principles of change are external to technological products and thus they cannot change by themselves: “a bed and a coat and anything else of that sort, qua receiving these designations – i.e. in so far as they are products of art – have no innate impulse to change” (Physics, 192b). Technological products cannot move by themselves. The cause of movement is external to the thing. Movement is either internal or external. If it is external, some mover must exist that have to be, in general, in permanent contact with the thing moved. Thus, artificial autonomous movement requires explanation. In the case of an arrow or of an automaton, the mover does not cause the movement continuously:

In addition to the naturally occurring up or down motion of bodies composed of earth, water, fire, and air, non-spontaneous motion observed in the world around us, such as the flight of an arrow, requires explanation. Aristotle envisioned all such motion as forced or violent (as against natural) motion. He proclaimed that such motion always requires an external mover, someone or something to apply an outside force of some sort to cause the motion in question. Moreover, the mover must be in constant contact with the object. In the vast majority of instances Aristotelian movers can be easily identified and the principle apparently confirmed: the horse pulls the cart, the wind blows the sail, and the hand guides the pen. But paradoxical counterexamples exist: the arrow or the javelin in flight after it has lost contact with its mover. Where is the mover in those cases? (Aristotle himself said the medium somehow does the pushing.) (McClellan & Dorn, 2006: 75).

Aristotle explains that a movement can sometimes be so violent that it can continue to act for some time without any contact between the mover and the moved thing:

pushing off occurs when the mover does not follow up the thing that it has moved; throwing when the mover causes a motion away from itself more violent than the natural locomotion of the thing moved, which continues its course so long as it is controlled by the motion imparted to it (Physics, 243a).

If this argument explains the flight of an arrow, the movements of automata remain still unexplained, for they tend to move autonomously for a too long period of time without the help of any external mover.

Aristotle considers the movement of automata and explains their capacity to move quasi-autonomously. Discussing animal movements, Aristotle compares animals with automata in Movement of Animals and Generation of Animals. Automata present a kind of self-movement by the fact that they, on the basis of design, can transform one kind of locomotion into another kind of locomotion. They are set in motion by a mover through a causal chain. This causal chain that affects only local motion is their substantial form and this is similar with the animal motion caused mechanically by the environment. The motion is potentially contained in the automata, i.e. the potential motion of automata was imprinted in them by the artisan.

It is possible, then, that A should move B, and B move C; that, in fact, the case should be the same as with the automatic puppets. For the parts of such puppets while at rest have a sort of potentiality of motion in them, and when any external force puts the first of them in motion, immediately the next is moved in actuality. As, then, in these automatic puppets the external force moves the parts in a certain sense (not by touching any part at the moment, but by having touched one previously) (Generation of Animals, 734b).

Aristotle accepts a limited² similitude between animals and automata – their constitutive physical parts are similar, their movements can be affected by their environment.

The movements of animals may be compared with those of automatic puppets, which are set going on the occasion of a tiny movement (the strings are released, and the pegs strike against one another); or with the toy wagon (for the child mounts on it and moves it straight forward, and yet it is moved in a circle owing to its wheels being of unequal diameter – the smaller acts like a centre on the same principle as the cylinders). Animals have parts of a similar kind, their organs, the sinewy tendons to wit and the bones; the bones are like the pegs and the iron; the tendons are like the strings; for when these are slackened or released movement begins. However, in the puppets and the toy wagon there is no change of quality (Movement of Animals, 701b, my emphasis).

However, automata lack qualitative change and also the internal principles of change. They can only transform the motion they receive without adding a surplus of motion. An automaton's causal chain can affect only local motion. For Aristotle, local motion is just one type of motion alongside change in quality, change in quantity, and generation-destruction. The four changes (change in quality, change in quantity, change of place and the generation-destruction) cannot be reduced just to one: “Aristotle ... never tries to reduce one kind of change to another; the difference of category stands as a barrier against any such attempt.” (Ross, 1995: 51). Although a change of place, locomotion, is involved in every change, this one is not fundamental and cannot explain the process of change as such. What is peculiar to automata is that based on their design they can transform the received motion. Automata cannot initiate movement and they cannot change into something else or evolve. The limit of the comparison is the local motion set by an external agent. Moreover, animals can continue to move by themselves while automata will stop when the imprinted artificial movement is consumed.

Knowledge and Techne

In the beginning of Metaphysics (980a-981b), Aristotle presents a historical evolution of knowledge from animal perception to philosophical contemplation. In this text Aristotle reaffirm the Platonic low status of technology as being an ignoble kind of knowledge. For Aristotle knowledge begins with perception, the possibility of every animal to distinguish differences. The faculty of perception gives rise to memory as the trace of perception in the soul. The next step is the experience that represents the creation of a certain universal based on multiple memories over the same thing. Experience is the origin, on the one hand, of science, epistheme, if the concern is Being as such, and, on the other hand, of art, techne, if the concern is becoming: “science and art come to men through experience” (Metaphysics, 981a). Art, techne, that comprises all Platonic classes, is inferior to knowledge because it is “limited in its interest by having some ulterior practical end” (Ross, 1995: 99): “when all such inventions were already established, the sciences which do not aim at giving pleasure or at the necessities of life were discovered” (Metaphysics, 981b). Utility is not a noble purpose for Aristotle. The real knowledge is the knowledge of universals and causes, not a description of how particulars are. Thus, in the first paragraphs of Metaphysics, Aristotle rejects techne as a lower activity, which obviously is not recommended for a citizen. At the end of his discussion on the origins of knowledge, Aristotle gives a hierarchy of knowledge with arts (techne) at the bottom and science (epistheme) at the top: “the man of experience is thought to be wiser than the possessors of any perception whatever, the artist wiser than the men of experience, the master-worker than the mechanic, and the theoretical kinds of knowledge to be more of the nature of wisdom than the productive” (Metaphysics, 981b).

Beside art (techne, making) and science (epistheme, “the disposition by virtue of which we demonstrate” (Nicomachean Ethics, 1139b)), Aristotle admits other three ways of knowing: a practical wisdom (phronesis, doing) dealing with living a good life, political or military actions, and taking good decisions; an intuitive reason (nous), the faculty that grasps the first principles, the universal truths; and finally the theoretical wisdom (sophia) that is the union of science and intuitive reason directed at the loftiest objects as heavenly bodies or God.³ Nevertheless, the faculties of knowledge can be reduced to three given that epistheme, nous and sophia have the common domain of studying the necessary and the immutable. Therefore, we have, in order of importance, proper knowledge dealing with the necessary, practical wisdom dealing with praxis and art dealing with making artificial things. The fact that techne does not possess real knowledge is made very clear in Magna Moralia, where Aristotle or its follower – the authenticity of the book is still disputed – considers the mechanics as being a bad branch of knowledge:

pleasure was held ... not to be good ... because some pleasures are bad. But this sort of objection and this kind of judgment is not peculiar to pleasure, but applies also to nature and knowledge. For there is such a thing as a bad nature, for example that of worms and beetles and of ignoble creatures generally ... In the same way there are bad branches of knowledge, for instance the mechanical (Magna Moralia, 1205a).

Knowledge
Of the necessary	Of the contingent
Science + Intuitive reason + Theoretical wisdom	Practical wisdom	Techne

Fig. 1. The division of Knowledge. After Ross, 1995, 137.

Technology posses a certain degree of knowledge, however ignoble. Aristotle affirms that mechanical knowledge is the practical subset of geometry. In fact, mechanics and music seem to be the only arts, techne, that possess a specific kind of knowledge: “But demonstration does not apply to another genus – except, as has been said, geometrical demonstrations apply to mechanical or optical demonstrations, and arithmetical to harmonical” (Posterior Analytics, 76a, my emphasis). On this account, mechanics and music seem to be, out of all other forms of techne, the most knowledgeable arts because they are most reducible to simple mathematical relations. Mechanics abstracts from real motions and it deals with geometrical figures and thus it has the characteristics of a science. Mechanics does not deal with objects qua objects but qua instantiating geometrical entities, lines and figures:

a science is most precise if it abstracts from movement, but if it takes account of movement, it is most precise if it deals with the primary movement, for this is the simplest; and of this again uniform movement is the simplest form. The same account may be given of harmonics and optics; for neither considers its objects qua light-ray or qua voice, but qua lines and numbers; but the latter are attributes proper to the former. And mechanics too proceeds in the same way (Metaphysics, 1078a, my emphasis).

Although mechanics is linked to geometry, the exchange between them is only in one direction: geometric principles can be applied in mechanics but geometry remains totally unchanged. Science is immutable while art only imitate some of its features. Science has nothing to gain from technical endeavours.

Classification of Techne

There are lower and higher forms of techne, based on the utility of technological products: higher utility of technological products corresponds to lower status of that technology. Artists belong to a higher level of human development than master artisans and artisans, although all of them deal only with particulars that do not qualify for real knowledge. Thus, if the products of artisans aim at satisfying the necessities of life, the associated techne has a lower status: “as more arts were invented, and some were directed to the necessities of life, others to its recreation, the inventors of the latter were always regarded as wiser than the inventors of the former, because their branches of knowledge did not aim at utility” (Metaphysics, 981b). This distinction classifies techne in two great domains, that of art – the playthings class in Platonic terminology – and technology as such.

Aristotle gives three criteria for classifying arts: the materiality involved in that art, the abilities that that specific art develops in men, and the contingency of that art. Thus, if an art requires an important involvement with material things, that art is more ignoble. Also, if an art requires more physical abilities at the expense of theoretical and practical ones, that art has a lower status⁴.

Those occupations are most truly arts in which there is the least element of chance; they are the meanest in which the body is most maltreated, the most servile in which there is the greatest use of the body, and the most illiberal in which there is the least need of excellence (Politics, 1258b, my emphasis).

Although in mechanics more geometrical principles are involved, this art is condemned by Aristotle because it requires a lot of physical work and its products are made for others to use them, transforming the technician into some kind of slave:

the artisan ... attains excellence in proportion as he becomes a slave. The meaner sort of mechanic has a special and separate slavery; and whereas the slave exists by nature, not so the shoemaker or other artisan (Politics, 1260b).

An art is nobler if it is closer to practical life, the exercise of citizenship. The practical life is attained only if one develops practical wisdom. Practical wisdom deals, like technology, with contingent beings. “The class of things that admit of variation includes both things made and actions done. But making is different from doing” (Nicomachean Ethics, 1140b). In the case of praxis there is on the one hand the nobility of purpose, the development of human personality, and on the other hand the fact that practical actions are ends in themselves. “[M]aking aims at an end distinct from the act of making, whereas in doing the end cannot be other than the act itself” (Nicomachean Ethics, 1140b). The separation between praxis and techne seems quite straightforward but in fact it is not so, at least for the modern mind, because if sculpture, architecture, mining, and carpentry belong to technology as expected, agriculture is on the borderline because it elevates the people who practice it:

Now in the course of nature the art of agriculture is prior, and next come those arts which extract the products of the earth, mining and the like. Agriculture ranks first because of its justice; for it does not take anything away from men, either with their consent, as do retail trading and the mercenary arts, or against their will, as do the warlike arts. Further, agriculture is natural; for by nature all derive their sustenance from their mother, and so men derive it from the earth. In addition to this it also conduces greatly to bravery; for it does not make men’s bodies unserviceable, as do the illiberal arts, but it renders them able to lead an open-air life and work hard; furthermore it makes them adventurous against the foe, for husbandmen are the only citizens whose property lies outside the fortifications. (Economics, 1343a-b)

Here Aristotle redesigns the Platonic classification of techne. Firstly, he divides techne into liberal and illiberal arts. Liberal arts, like music, are noble arts because they do not involve utility and develop human superior abilities. Secondly, Aristotle classifies the illiberal arts on the basis of their closeness to practical life. Thus, agriculture is the first of illiberal arts because it develops liberal character traits.

The ancients certainly used technologies and techniques in the actual practice of agriculture, but they considered it to be conducive to the development of good character traits in the landholder that would prepare him for political and military action. They believed that agriculture inculcated virtue, training elite males to be good leaders. It was a discipline appropriate to the praxis of political and military leadership, quite separate from lower-status occupations involving the technical arts. (Long, 2001: 16).

After agriculture comes what Plato called 'first-born' class, obtaining the raw materials. The last position is occupied by mechanics, which is closest to slavery, the opposite of citizenship. Aristotle shows that science and practice are superior to technical endeavours and beside that, he prohibits the mixing of these domains. The borders are clear and distinct and cannot be trespassed. It will be the task of the Renaissance to show the important links between science and technology.

The Social Status of Technology

As already mentioned, technology is classified between slavery and practical life with different degrees of excellence. Aristotle wrote many passages in which he denies citizenship to artisans and limits the involvement of citizens with arts, especially illiberal arts. Even music or gymnastics can become illiberal if pursued immoderately:

nor is there any difficulty in meeting the objection of those who say that the study of music is mechanical. ... it is quite possible that certain methods of teaching and learning music do really have a degrading effect. It is evident then that the learning of music ought not to impede the business of riper years, or to degrade the body (Politics, 1340b-1341a)

From the above quotes one can see that to become a technician is shameful. Artisans do not deserve to be citizens:

There still remains one more question about the citizen: Is he only a true citizen who has a share of office, or is the mechanic to be included? ... In ancient times, and among some nations, the artisan class were slaves or foreigners, and therefore the majority of them are so now. The best form of state will not admit them to citizenship; but if they are admitted, then our definition of the excellence of a citizen will not apply to every citizen, nor to every free man as such, but only to those who are freed from necessary services. The necessary people are either slaves who minister to the wants of individuals, or mechanics and labourers who are the servants of the community. ... so that under some governments the mechanic and the labourer will be citizens, but not in others, as, for example, in so-called aristocracies, if there are any, in which honours are given according to excellence and merit; for no man can practise excellence who is living the life of a mechanic or labourer. In oligarchies the qualification for office is high, and therefore no labourer can ever be a citizen; but a mechanic may, for an actual majority of them are rich. At Thebes there was a law that no man could hold office who had not retired from business for ten years. (Politics, 1277b-1278a)

The mechanic, because he works for others and is paid for that, is just a different kind of slave. In conclusion, it is dishonourable for citizens to involve in such activities:

Certainly the good man and the statesman and the good citizen ought not to learn the crafts of inferiors except for their own occasional use; if they habitually practice them, there will cease to be a distinction between master and slave ... There is, indeed, the rule of a master, which is concerned with menial offices – the master need not know how to perform these, but may employ others in the execution of them: the other would be degrading; and by the other I mean the power actually to do menial duties, which vary much in character and are executed by various classes of slaves, such, for example, as handicraftsmen, who, as their name signifies, live by the labor of their hands – under these the mechanic is included (Politics, 1277b).

Aristotle uses the Platonic argument that the technician does not even know the standards of what he is doing. His products are subject to users' opinions who best evaluate them.

Moreover, there are some arts whose products are not judged of solely, or best, by the artists themselves, namely those arts whose products are recognized even by those who do not possess the art; for example, the knowledge of the house is not limited to the builder only; the user, or, in other words, the master, of the house will actually be a better judge than the builder, just as the pilot will judge better of a rudder than the carpenter, and the guest will judge better of a feast than the cook. (Politics, 1282a)

An important Ancient work on technology is pseudo-Aristotle's Mechanics, which, in the introduction, critically analyses the relation between technology and nature, a book that tremendously influenced the Renaissance. This book is consistent with the Aristotelian corpus and during the Renaissance it was considered an original work of the Stagirite. All contemporary literature, however, agrees that the Mechanics is not written by Aristotle. 

The fact that it was attributed to Aristotle raises its value in the eyes of a Renaissance man. As for the real author, David Ross and G.E.R. Lloyd think that it is somebody from the Peripatetic School while Thomas Winter tries to show by elimination of possible authors that the book was written by a Pythagorean contemporary of Plato, Archytas of Terentum, the inventor of mathematical mechanics (Winter, 2007: iii-ix).

The book was considered unique amongst Aristotle's work because it focuses on simple machines, describing pulleys, gears, levers, and other devices that produce mechanical advantage and also because it mixes physics and mathematics in treating mechanical problems. Mechanics is copied in 1457 for cardinal Bessarion but at the time of its discovery there is little interest in its content.

“For nearly a hundred years thereafter, its main readers were humanist scribes and scholars who had little interest in its contents, but at the turn of the sixteenth century, around the time of its first Greek printing in the Aldine edition of Aristotle (1495-8), researchers began to look at the Mechanics more closely, creating demand for improved editions, Latin translations, vernacular versions, and commentaries that made the work more widely available.” (Copenhaver, 1992: 66).

The initial lack of interest shows the traditional contempt of both scholars and humanists for technology.

Mechanics begins by establishing the categorical difference between art and nature. Mechanics is not a part of physics because mechanics is para physin. This can be interpreted either as “contrary to nature” or as “beyond nature” in the sense of completion of nature. Anyway, nature and mechanics are separated. What is important and non-Aristotelian about the conception of technology in this book is the fact that mechanics use both physics and mathematics and mix them in creating artefacts.

They [mechanical problems] are not quite identical nor yet entirely unconnected with Natural Problems. They have something in common both with Mathematical and with Natural Speculations; for while Mathematics demonstrates how phenomena come to pass, Natural Science demonstrates in what medium they occur” (Mechanics, 847a)

The marvels of mechanics are all explained by the marvellous status of circular motion because the circle is a combination of opposites and the authors of Mechanics tries to demonstrate that any mechanism is reducible to circles:

there is nothing strange in the circle being the origin of any and every marvel. The phenomena observed in the balance can be referred to the circle, and those observed in the lever to the balance; while practically all the other phenomena of mechanical motion are connected with the lever (Mechanics, 848a).

The oppositions contained in the circle are the existence of concavity and convexity in the same circumference, the backward and forward movement in the same time¹, the possibility of movement in circumference while the centre is at rest and the fact that a point farther from the centre moves faster than a point closer to the centre. Therefore, the author will try to explain all the problems by reducing them to circular motion. After the introduction, the Mechanics continues with thirty-five problems or mechanical phenomena, some taken from everyday experience and others of more theoretical nature. It is important to notice that in the Aristotelian corpus there is no mention of mechanisms that use fire, water or wind. This characteristic is overcome by Hellenistic authors who made extensive use of these phenomena in constructing their mechanisms: both Hero and Vitruvius describe the aeolipile, the first recorded steam engine in history.

Apart from the works mentioned above, there is no other philosophical approach to technology before Renaissance. The most proeminent examples of Ancient technology authors are Hero of Alexandria, Vitruvius and Archimedes, who design and describe complex mechanisms but their intentions are neither philosophical nor scientific. The closest we get to a view on the role of technology in those authors is Hero's comment on the aim of his work, that of bringing “much advantage ... to those who shall hereafter devote themselves to the study of mathematics” (Hero of Alexandria, 1851:1). And after a short introduction on the problem of vacuum and on the elements, he proceeds to describe diverse mechanisms.

1A similar passage is found in Fragments: “art exists to aid nature and to fill up what nature leaves undone. For some things nature seems able to complete by itself without aid, but others it does with difficulty or cannot do at all; ... similarly, some animals too attain their full nature by themselves, but man needs many arts for his preservation, both at birth and in the matter of nutrition later” (I Dialogues, Iamblichus, Protrepticus 49.3-51.6 Pistelli, B13)


2 “Animals – unlike stones or artifacts – can instigate local motion when there are changes in their environment, but nothing pushing or pulling them. The automata he describes do not precisely do this, but they share with self-movers the capacity to transform one kind of input into motion of a different kind. In the puppets Aristotle uses as analogues, the unwinding of twisted cords is transformed into the motion of the limbs. The sequence of motion continues without an agent operating it, and unlike a projectile – which simply continues the motion it is given – it is the constitution of an automaton that determines the resultant motion” (Berryman, 2003: 358)


3 “Let it be assumed that the states by virtue of which the soul possesses truth by way of affirmation or denial are five in number, i.e. art, knowledge, practical wisdom, philosophic wisdom, comprehension; for belief and opinion may be mistaken.” (Nichomachean Ethics, 1139b)


4 “parents who devote their children to gymnastics while they neglect their necessary education, in reality make them mechanics” (1338b)