S Y N A E S T H E S I A ----------------------------------- AND

The Wheel of the Five Senses
Longthorpe Tower




The Synaesthetic Phenomenon

When we speak of various types of communication that are perceived through the combination of two or more senses and are integrated and focused at the level of meaning, we are, of course, speaking about the phenomenon that goes under the name of synaesthesia.

Grosso modo, synaesthesia is a kind of intertransposition based on the interaction of the sensory experience during the act of perception. As such, it belongs to the realm of metaphor. Yet it can be considered more than a simple metaphor.

Linguistically, in synaesthesia there is no actual displacement of the "real" sign as in metaphor. Here neither of the two real signs displaces the other. However, the signs do enter into a form of simultaneous and synergetic association, and by so doing create a virtual image that constitutes a global semantic transposition of each and all "real" signs involved. A synaesthetic perception is one derived from the specific semantic area designed by the lexicon pertaining to sensory images. As such, synaesthesia is a kind of semantic metaphoric fusion of two or more sensory perceptions.

It is a commonplace that literary synaesthesia1 is one of the canonic forms of expression in modern poetry. However, the concept of synaesthetic perception is a very ancient one, and the literary practice can be traced all the way back to Bible2. In the Western world the idea can be attributed to Aristotle. In fact, it was one of the underlying assumptions that prompted him to develop a theory of the "common" or central sense as a comprehensive perception and thus constituting one of the basic structures in Aristotle's conception of man's cognitive powers.

The idea was discussed and elaborated first by the Hellenistic and Byzantine commentators on Aristotle, who also used the term συναίσθησις ("synaísthesis") for the first time3. It was then revived by the philosophical and psychological analyses of the Schoolmen—both in Paris and Bologna as well as at Oxford. Later it captured the attention of poets and writers on poetics in post-Italian Renaissance. And finally it developed as one of the basic ingredients in Symbolist and post-Symbolist poetics down to our day.

It may be appropriate to mention that by the end of the thirteenth century poets, too, were not only cognizant of these ideas, but were able to texture them into their verses—as Dante Alighieri frequently did in his Divine Comedy.

Although in his theoretical writings there is no overt evidence for synaesthesia4, references implying that Dante was well and directly aware of the concept can be found, at least, in a couple of related passages from the Convivio (3.9.6). Making precise references to the two works of Aristotle in which the doctrine of "common sense" is developed, Dante affirms that only color and light can properly be said to pertain to the visual sense:

«Dove è da sapere che, propriamente, è visibile lo colore e la luce, sì come Aristotile vuole nel secondo de l'Anima, e nel libro del Senso e sensato»

("One must know that, properly, only color and light are visible, as Aristotle states in the second book of De anima, and in the treatise De sensu et sensato").

Dante adds that, to be sure, other things come into the field of sight and therefore are visible, but not properly visible as in the case of color and light:

«Ben è altra cosa visibile, ma non propriamente, però che5 altro senso sente quello, sì che non si può dire che sia propriamente visibile, né propriamente tangibile; sì come è la figura, la grandezza, lo numero, lo movimento e lo star fermo, che sensibili ‹comuni› si chiamano: le quali cose con più sensi comprendiamo»

("Other things are also visible, but not properly since another sense perceives them. Therefore we cannot say that they are properly visible or properly tangible. These are figure, size, number, movement, and stasis. These are called ‹common› sensible objects as we perceive them with more than one sense").

Here Dante applies the Aristotelian doctrine pertaining to the distinction between the so called sensibilia propria

(Dico autem [sensibile] proprium quidem, quod non contigit altero senso sentiri ... ut visus coloris, et auditus soni, et gustus saporis.

I am saying that proper sensible objects are those which are not perceived by other sense ... sight perceives only color, hearing only sound, and taste only flavor.)

and sensibilia communia

(Communia autem sunt motus, quies, numerus, figura, magnitudo: huiusmodi enim nullius sensus sunt propria, sed communia omnibus.

Common sensible objects on the other hand are movement, stasis, number, figure, size: they are not proper to any individual sense, but common to all)6.

This doctrine became one of the basic point for all twelfth and thirteenth centuries commentators of the two works of Aristotle mentioned by Dante, from Averroës and Alexander of Hales to Albertus Magnus and Thomas Aquinas. The discussion centers on the common sense.

According to Aristotle, sensus communis, or common sense, is the one function of the ψυχή that gains perceptions of all objects, a common central organ of perception in which the separate communications received by the proper senses are combined into a unity. Common sense can also display synthetic power by grasping the common properties in he qualities of the common sensibles. In fact, the common sensibles (movement, figure, etc.) are the proper objects of the common sense. In addition, common sense has the power to separate and distinguish among the various sensations, and yet it must preserve the unity of sense perception. In short, it is the common ground, "the fontal principle of all external senses", as Thomas Aquinas puts it in his commentary on Aristotle's De anima, and as Dante himself calls it in the same chapter of Convivio (3.9.9) quoted above:

«Di questa pupilla lo spirito visivo, che si continua da essa, a la parte del cerebro dinanzi, dov'è la sensibile virtute sì come in principio fontale, subitamente senza tempo la ripresenta, e così vedemo».

"The spirit of vision from the pupil is transmitted to the frontal lobe of the brain, where the sensitive power is located, as in a fontal principle. Thus the image is represented immediately, without lapse of time, and we see".

In accordance with the medical tradition of his time, Dante assigns the seat of the common sense «a la parte del cerebro dinanzi», namely to the first of the three ventricles in which, besides common sense, also fantasy, or imagination, is located. This placement is reiterated by Dante in a passage from the Vita Nuova, which reads, «lo spirito animale dimora ne l'alta camera ne la quale tutti li spiriti sensitivi portano le loro percezioni» (2.5) (The sensitive spirit dwells in the high chamber [i.e. the brain] to which all other sensitive spirits bring their perceptions). While not all Aristotle's commentators were in agreement as to the location of the sensus communis7, they all agree that it had the power, through the medium of the proper senses, to bring together and unite two or more sensations. Thus for Alexander of Hales,

Sensus communis habet primum actum et singularem, scilicet discernere album a dulci vel conferre ... Si enim discernit album a dulci et confert, necesse est recipi formam utriusque in uno organo: illud non erit organum gustus nec organum visus ... [sed] sensus communis. Non differt sensus communis sensibilis in suo sensibili a particularibus: quinque enim sensibilia, quae sunt magnitudo, motus, numerus, figura, quies, quae sunt communia sensuum particularium, etiam sunt propria sensus communis. Apprehendatur etiam sensibilia sensum particularium a sensu communi: nam aliter non posset inter illa distinguere; ergo necesse est differre sensum communem in obiecto a sensibus particularibus.

Common sense is responsible for a fundamental and specific activity: namely, that of discerning white from sweet and that of conflating them ... In fact, if white and sweet are perceived separately and combined together, it is necessary that the forms of each be perceived by a single organ. This cannot be the sense of taste or the sense of sight, but a common ense. Insofar its own and proper field, the perseption by common sense does not differ from that of the particular senses. In fact, the five common sensibles—size, movement, number, figure, and stasis—are common to the particular senses, and proper to the common sense. Particular objects perceived individually by the particular senses are also perceived by the common sense. Otherwise it could not distinguish among them. It is necessary therefore to make a distintion between common sense and particular senses8.

Alexander of Hale's point of view was followed closely by other major Schoolmen. Thus, for Thomas common sense—which, again, is the "fontal root of all senses"—could be considered in two ways. First, it could be taken as the terminus of a sensation perceived by an external sense: for instance, the perception of white by the organ of sight. Second, it could be taken as the principium and terminus of a sensation perceived by any and all external senses: for instance, the perception of sweet by he organ of taste in relation to the perception of white. In this manner, common sense is able not only to perceive the difference between white and sweet, but also to conceive and realize that in certain cases white is indeed joined with sweet, as in the case of sugar.

Vis sentiendi diffunditur in organa quinque sensum ab alia una radice communi, a quo procedit vis sentiendi in omnia organa, ad quam etiam terminatur omnes immutationes singulorum organorum: quae potest considerari dupliciter. Uno modo, prout est principium unum et terminus omnium sensibilium immutationum. Alio modo, prout est principium et terminus huius et illius sensus ... Habet igitur hoc principium sensitivum commune, quod simul cognosca plura, inquantum accipitur bis ut terminus duarum immutationum sensibilium; inquantum vero est unum, iudicare potest differentiam unius et alterum. ... Ultimo iudicium et ultima discretio pertinet ad sensum communem.

The power of perception comes to the organ of the five senses from one common root. The power of perception derives from it, and all perceptions gathered by the individual senses terminate in it. This can be considered from two points of view. One, as beginning and end of all sense perceptions. Two, as beginning and end of of this or that individual sense. ... This common sensitive foundation, which knows many things at once, holds power in two ways: first, insofar as it is taken twice as end of two sensitive perceptions; second, insofar as it is taken as one, it can judge the difference of one and the other perception. The final judgment rests with the common sense9.

The same concepts are reiterated by Thomas in several passages of his Summa. For instance, in the question on the "powers of the soul taken specifically", Aquinas dedicates two full articles to the matter we have been considering. He describes what we now call synaesthesia not as the result of a psychic disorder10 but as the normal process of decodification and integration of various sensory perceptions. Nor does he consider it as a simple perception of one sense modality in terms of another, but sees it as a totality that envelops the whole field of perception itself in relation to knowledge, in which fantasy-imagination (phantasia sive imagination) and memory—considered respectively as the treasure-stores (thesaurus) of sense-forms and of intentions—play a fundamental and indisputable role. A basic schematic diagram illustrating the direction of this totality of perception, as expressed by Thomas in Summa Theologica 1a, q.78, a.4, may look something like the following

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Totality of perception according to Thomas Aquinas
Diagram 1

While memory, in a way, can be considered to contain the total gestalt, in the reflection of Thomas the basic working mechanism to which synaesthesia could be ascribed would be under the control of common sense and imagination. These two powers, however, work in strict correlation with the phantasms. Phantasmata, in fact, are not only the images presented to the imagination by the activity of the exterior things affecting the the different and individual sensory powers (i. e., visual, auditory, olfactory, tactile, and gustatory images), but they also present a "certain natural order linking different images to each other, e. g., a unity accruing to them from a definite area and time that serve as focal points for different sensations"11. Hence, a synaesthetic operation would topographically occupy the entire lower half of the diagram.

When memory seems to have lost the context of an image, what has really happened is that fantasy has taken over. The function of the common sense is to perform a kind of synapse of the sense forms apprehended by the individual senses. So that while sight, for instance, can discern white from black or green, and taste can understand sweet, "neither sight nor taste can discern the difference between white and sweet; because in order to discern the difference between two things it is necessary to know them both. Therefore it is necessary that such a judgment belong to a common sense to which all sense perceptions are referred, as to a common terminus" (Summa theol., 1a. 78. 4. 2).In fact, "sometimes we know separately things that are conjoined in reality; for instance, something is white and sweet, and yet sight knows only the whiteness and taste only the sweetness"12.

Leaving aside momentarily the treasure-store of fantasy, it seems clear that common sense is responsible for the process of decodification and integration of diverse and divergent sensations in order to move toward the level of association.

The idea of common sense as a common terminus is predicated on the analogy Aristotle drew between it and the mathematical point13. Thomas Aquinas says that any point between the two ends of a line can be considered as either one or as two. He underscores this analogy in a comment to De sensu et sensato where the underlying concept of synaesthesia once again becomes apparent:

Punctum autem, quod est terminus diversarum linearum, secundum quod in se consideratur, est unum et indivisibile. Et isto modo sensus communis secundum quod in se est unum, est indivisibilis et est unum sensitivum actu dulcis et albi: dulcis per gustum et albi per visum. Si vero consideratur puntum seorsum ut est terminus huius lineae, sic est quodammodo divisibile, quia utimur uno puncto ut duabus. Et similiter sensus communis, quando accipitur ut divisibile quoddam, puta cum seorsum iudicat de albo et iudicat de dulci est alterum secundum actum: secundum vero quod est unum, iudicat differentias sensibilium.

The point, as the end of various lines, when considered itself is one and indivisible. In the same manner, common sense, considered in itself, is also one and indivisible, because it has the power to combine in a single sensitive activity sweet and white: sweet as perceived by taste, and white as perceived by sight. If, on the other hand, we consider the point as the end of one single line, the point is divisible because we use one point as the end of two, or more, lines. In the same manner common sense, when taken as divisible (as when it gives judgment on white and sweet) is one or the other according to the activity performed14.

The Synaesthetic Wheel

It must be noted that the early commentators on Aristotle, such as Alexander of Aphrodisias and Themistius, came to regard the Aristotelian point as a center of a circle from which, as many, a number of radii start and in which, as one, they all unite. This observation is common to almost all medieval commentators as well, beginning, by way of preminence, with "The Commentator" himself, Averroës, in the twelfth century , and up to Albertus Magnus and Thomas Aquinas in the next century. Averroës pointed out that since it was difficult to explain the concept of the sensus communis, Aristotle had to be praised for comparing it to the mathematical point. He went on to say that the function of the common sense "is one and many, as that of the point which is the center of the circle when many lines are drawn from the center to the circonference"15. But it is perhaps Albertus Magnus that gives one of the more complex comment on the subject:

... dicemus sensum communem essentialiter ac formaliter unum et indivisibilem esse et per subiecta particularia, ad quae dirigitur virtus eius, esse plures eo modo quidem mathematici dicunt punctum in circulo, qui dicitur centro, esse unum in substantia et forma, non in quanto duo sunt, quia sic in se indivisibile est et non ex diversis compositum et hoc modo non discernit nisi unum, quod est medium circuli ... In quanto vero est unum in substantia et forma mediationis, fit iudicium unius et multorum unitorum uno quodam et simul. Unius enim totius circulationis iudicium est unum centrum, et multarum linearum aequalium est iudicium per unicam centri mediationem, eo quod illa causa universalis est omnis aequalitatis quae est in lineis ab eodem centro ad circumferentiam protractis.

... We maintain that common sense , in its essence and form, is one and indivisible. But in relation to its powers, when directed to particular objects of sensation, it is more than one. In the same manner—as mathematicians affirm—of the point of a circle, its center, which is one in substance and form, because it is indivisible in itself and is not composed by several, and as such it discerns only one quality, that is the center of the circle. ... However, in so far as it is one in essense and form of mediation, it pronounces judgment of one and many in a certain way and at once. In fact only one center has the power of judgment over the entire circulation, and the judgement of the many equal lines is a single mediation of the center. This constitutes a universal cause of equality of all the lines that are drawn from the same center to the circumference16.

Indeed, by the end of the thirteenth century the common sense had become firmly and widely established as analogous to the center point of the circle and the relation which the center has with its radii proceeding from the circumference and terminating on it, and vice versa.

The doctrine of the common sense and the underlying concept of synaesthesia—in fact, the concept itself of its tradition, namely the analogy of the point and its development into the center of the circle—can be well illustrated by the so-called Wheel of the Five Senses, a medieval wall painting in Longthorpo Tower (near Peterborough, England) discovered some fifty years ago and said to have been made before 1340.

Click to view larger image

The painting17 portrays the figure of a king standing behind a five-spoked wheel which he apparently holds in place with his left hand. The king's head is turned toward his right as he seems to look over a spider web outside the wheel. Surrounding the wheel, from the king's right to his left, at the points where the spokes connect to the rim, are five animals: a spider in its web, a eagle or vulture, a monkey, a cock, and a boar. According to a passage from De rerum natura by Thomas of Cantimpré, each of the five animals represents a sense18. Now for our purpose, this painting may be considered as the first known visual representation19 of the connections among the five senses, both in relation to the sense of touch (scholastically understood as the most important sense, in that it is the foundation of all senses and the closest "to the fontal root", that is common sense)20 and in relation to the king, who may be considered to represent man's ratio.

Insofar as the process of perception is concerned, we may therefore say that each animal, taken by itself, represents the "aesthetic" or sense level. The fact that in the painting the senses are correlated to the rim of the wheel is quite significant. The spokes may represent the sensorial channels of perceptions leading to a center, the hub of the wheel—an inter-aesthetic point where decodification and integration of various sensory perceptions take place. This area is under the control of the common sense, which sets up for the ratio, and hence for the intellect, the associational meaning of two or more sensory perceptions. For our discussion, then, we may call this painting in Longthorpe Tower not simply The Wheel of the Five Senses, but The Synaesthetic Wheel21.

© 2004 - Gino Casagrande


* This note is part of an article on the "visible speech" in Dante's Purgatorio (x, 55-63). The article was first read in 1986 at The Newberry Library in Chicago. It was then revised and published, with the title "«Esto visibile parlare». A Synaerhetic Approach to Purgatorio 10. 55-63", in Lectura Dantis Newberryana, Vol. II, Evanston:Northwestern University Press, 1990, pp. 21-57. For an interpretation of The Wheel of the Five Senses, see G. Casagrande and Ch. Kleinhenz, "Literary and Philosophical Perspectives on the Wheel of the Five Senses in Longthorpe Tower", Traditio 41(1985): 311-327. The image of the Longthorpe Tower Wheel of the Five Senses is taken from this article (plate facing p. 326). For acknowledgement for the permission to reproduce this photograph, please see the Traditio article on page 311, note 2.

1. Literary synaesthesia goes also under the name of "intersense analogy". Presumably this is in order to distinguish it from clinical synaesthesia, which is often associated with abnormal experience. For more detail, see G. O'Malley, "Literary Synaesthesia", Journal of Aesthetic and Art Criticism 15 (1957):391-411. However, there may be no need to make such a distinction since clinical synaesthesia is properly called 'synaesthesis' (see P. Dombi Erzsébet, "Synaesthesia and Poetry", Poetics 11(1974):23-44.

2. We can point at least to Exodus 20.18: Cunctus autem populus videbat voces et lampadas et sonitum bucinae (Cf. Biblia iuxta vulgatam versionem, ed. Robert Weber cum sociis..., 4th edition, Deutsche Bibelgesellschaft 1994, p. 105).

3. The term was first used by Alexander of Aphrodisias in relation to consciousness of sensation which accompanies the exercise of man's perceptual powers and is under the control of the common sense (E. Wallace, Aristotle's Psychology [New York, 1976], pp. lxxxi-lxxxii and 225; this is a reprint of the 1882 ed., entitled Peri pshychês). In the past many scholars have supposed that synaesthesia is a modern phenomenon that began with Romanticism. Recent investigations, however, have shown that such an assumption is unfounded and incorrect. O'Malley (p. 391) has pointed out that a basic definition of synaesthesia as the "metaphor of the senses" is suggested by a remark of Aristotle in De anima 2. 420a-b (but see also De anima 2. 9. 421a-b). In addition, by Aristotle, see De sensu et sensato 4. 440b.30. Cf. also Themistius, In de anima 104.

4. G. Cambon, "Synaesthesia in the Divine Comedy", Dante Studies 88(1970): 1-16.

5. I am quoting from Busnelli and Vandelli edition of Convivio (2d. ed., Edited by A. E. Quaglio, Florence 1964), p. 368. However, I am omitting their textual addition of "[anche]" to the text following "però che" and preceding "altro senso". Such an addition has been correctly judged inutile by M. Simonelli (Materiali per un'edizione critica del Convivio di Dante, Rome 1970, p. 156). For the other addition of "[comuni]" in the same paragraph, see n. 8 below.

6. De anima 2.6; 418a 10-20, in Thomas Aquinas, In Aristotelis Librum de anima, ed. by A. M. Pirotta, O.P., Turin 1959, p. 99 (hereafter In de anima).

7. "Quaeritur de instrumento sensus communi. Et videtur quod sit aliqua pars cerebri. ... Sed Philosophus arguit eius organum esse cor velut aliquid simile cordis in non habentibus cor" ("The discussion is about the organ of common sense. It seems to be located in a certain part of the brain. ... However, Aristotle argues that it is in the heart, or something similar to the heart in creatures without a heart"). Alexander of Hales, Summa theologica 1a. 2i. 360 (Quaracchi, 2: 437-438).

8. Cf. Alexander of Hales, op. cit. The textual addition of "[comuni]" to "sensibili" in Dante's Convivio 3.9.6 was first proposed by M. Romani in 1862, who placed it before the noun. In 1874, G. B. Giuliani accepted Romani's addition but placed it after the noun, so as to read "sensibili [comuni]". This addition was also defended by E. Moore in 1896, who has since been credited for it (cf. Il Convivio, ed. by Busnelli and Vandelli, 1: 367-368, n. 5). The addition is now accepted by all editions, since it is claimed that it is necessary for the meaning. Elsewhere in the Convivio (4. 8. 6) Dante in fact does use the expression "sensibili comuni". Thomas Aquinas uses the expressions sensibila propria and sensibilia communia as almost constant terms in his works (cf. In de anima 2. lect. 13; Comm. de sensu et sensato, lect. 2. 28ff.; Summa theol., 1a. 78. 3 ad 3; etc.).

9. Thomas Aquinas, In de anima 3. lect. 3. 609, 613. According to Thomas, the fundamental basis for the organic common sense is to be found in the sense of touch, but not intended as a proper sense—that is to say, as a touch-sense that can perceive contraries within its range, such as hot and cold, moist and dry, and so on (Summa theol. 1a. 73. 3 ad 3). As such the sense of touch is the foundation of all senses, and consequently it is the closest to the "fontal root of all senses", that is, the organic common sense. Thomas' view is also made clear in his commentary to Aristotle's De anima (3. lect. 3. 602): "‹Tactus› est primus sensuum et quodammodo radix et fundamentum omnium sensuum. ... Attribuitur autem ista discretio tactui non secundum quod tactus aest sensus proprius, sed secundum quod est fundamentum omnium sensuum et propinquius se habens ad fontalem radicem omnium sensuum, qui est sensus communis" (‹Touch› is the first and in a way the root and foundation of all senses. ... This power is attributed to the sense of touch not as a proper sense, but because it is the foundation of all senses and the closest to the fontal root of all senses, which is common sense"). See also n. 20 below.

10. "Attempts to establish it [i. e., synaesthesia] as in itself a sign of illness, degeneration and decadence seems to be inspired largely by prejudice or ignorance" (A. G. Engstrom, "Synaesthesia", Encyclopaedia of Poetry and Poetics, Princeton 1965, p. 840.

11. For a detailed description and in-depth analysis of the Thomistic conception of the soul and its cognitive powers in relation to knowledge, se, among others, L. M. Regis, O.P., Epistemology, New York 1959, pp. 157-308.

12. Cf. Summa contra gentiles 2. 75 1551: "Quae enim coniuncta sunt in re, interdum divisim cognoscuntur; simul enim una res est alba et dulcis: visus tamen cognoscit solam albedinem, et gustus solam dulceduinem" (Things which are united in the reality are nonetheless perceived separately, as for instance when something is white and sweet; sight perceives only whiteness, and taste only sweetness").

13. Cf. Aristotle's De anima 3.2 (427a 9-14).

14. Cf. Thomas Aquinas, In Aristotelis Librum de sensu et sensato, Taurini 1949, p. 81, n.288.

15. Averrois Cordubensis, Commentarium magnum in Aristotelis De anima libros, ed. by F. Stuart Crawford, Cambridge 1953, 149. 355-56.

16. Albertus Magnus, De anima 2.4.11.

17. Cf. E. Clive-Rouse and A. Baker, "The Wall-Paintings of Longthorpe Tower", Archaeologia 96 (1955): 1-57 and plate 17.

18. It would seem that only four of the five animals shown on the rim of the Longthorpe Tower wheel correspond to the animals representing the five sense according to Thomas of Cantimpré. See his Liber de natura rerum, ed. H. Boepse, berlin-New York 1973, 1. lib. 4, cap. 1, lines 190-194.

19. With the exception of an earlier but differently executed fresco depicting the five senses and found in the Abbazia delle Tre Fontana in Rome. In his study, Carlo Bertelli ("L'enciclopedia delle Tre Fontane", Paragone 235[1969]: 24-49) has pointed out the similarities between this fresco and the one in Longthorpe Tower.

20. Thomas Aquinas, Summa theol. 1a. 73. 3 ad 3, and 1a. 76. 5; In de anima 2. lect. 19. 484; 3. lect. 3, 602; lect. 17. 849; lect. 18. 865. See also Alexander of Hales's Summa theologica 1a. 2i. 355; and cf. n.9 above.

21. The synaesthetic process may be further clarified by the diagram below. The dotted lines starting at the terminus of each sensation (at the arrowheads) and intersecting the bands or channels of various senses might be taken to represent the mechanism (scanning and combining) of the common sense. This diagram may be read downward. In its schematic form, it conveys the idea represented by the Synaestheic Wheel in Longthorpo Tower.

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Diagram 2

Now, According to Thomas Aquinas, two activities take place at the sensory level (in parte sensitiva). This first, just described and illustrated by the the Synaesthetic Wheel, is of course effected from the outside by sensible objects. So, at the "aesthetic" level for instance, the sense of sight will be able to see only the color of an apple and not perceive its characteristic fragrance. But the fact that the apple is perceived without its scent can only be attributed to sight, because in the sense of sight there is only the image of color and not that of fragrance (Summa theol.1a. q. 85, a. 2 ad 2). It is, as we have seen, the function of the common sense to integrate the two perceptions. The other activity at the sensory level is a kind of pro-duction on the part of the imagination, in that it forms for itself the image of an absent object, or even an object never seen before (see also Diagram 1, above).

Both of these activities are controlled by the intellect. However, it is by virtue of the second operation that definitions and acts of meaning are formed by the combination and separation of ideas. These, in turn, are expressed through words. Single words express the definition, while words in the syntagmatic union of enunciation express the intellectual process of composition and separation—that is to say, meaning (cf. Thomas Aquinas, Summa theol. 1a. 85. 2 ad 2). The operation of the intellect, as an operation, is closely related to that of the common sense. In fact, the intellect is to imagination as common sense is to common sensation. This is an analogy in the strictest sense and holds true in relation to non homogeneous sensations such as white and sweet, as well as opposite sensations such as white and black. As common sense "judges" the sensations of white and black or of white and sweet, so intellect "judges" the phantasms of white and black or of white and sweet (cf. In de anima 3, lect. 12, 770). The intellectual process of conjunction is, of course, purely synthetic. The intellect has the power to abstract and synthesize two or more distinct concepts and merge them into one (cf. Thomas Aquinas, In de anima 3, lect. 11, 757-759. For a detailed analysis of the intellectual faculty of abstraction and composition, see B. G. Lonergan, S. J., Verbum: Word and Ideas in Aquinas, Notre Dame, Indiana, 1967. See also P. T. Durbin, "Unity of Composition in Judgment", The Thomist 31, 1967, pp. 83-120).

It seems obvious, then, that between sensation and imagination (and, indeed, also memory, which when it loses the context of an image is in fact relinquishing it to fantasy) there is a normal condition of anastomosis. It may be said that we have reached the fontal principle from which fine art springs.

Suffice it to say that while these ideas comprise quite an important stage in the considerations and reflections of Thomas Aquinas, they were also the object of an intensive and in-depth analysis by other Schoolmen. Naturally they also formed part of the inheritance of other thinkers, philosophers and learned people in general of the late Middle Ages, including, of course, the artist of The Synaestheic Wheel.

© 2004 - Gino Casagrande