The Corner-Stone

~René Guénon

The symbolism of the corner-stone in Christian tradition is founded on the text: “The stone which the builders rejected is become the head of the corner”.[2] It is odd that this symbolism is frequently misunderstood as a result of the confusion commonly made between this “corner-stone” and the “foundation stone”, suggested by the even better known text: “Thou art Peter, and upon this rock I will build my church and the gates of hell shall not prevail against it.”[3] This confusion seems strange for, from a specifically Christian point of view, it confuses Saint Peter with Christ himself, for it is the latter who is expressly meant by the corner-stone, as is shown in the passage from St. Paul, which distinguishes it particularly from the “foundations” of the building: “Ye are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner-stone, (summa angulari lapide) in whom all the building, fitly framed together groweth unto an holy temple in the Lord: in whom ye are builded together for an habitation of God through the Spirit” (literally “built together”, coedificamini) .[4] 

If the misunder­standing here were a purely modern one there would be no great cause for surprise, but it certainly seems already present in former times when it would be scarcely possible to attribute it simply and solely to an ignorance of the symbolism; thus one is drawn to speculate whether, in fact, there is instead, in the first place, some question of an intentional substitution, reflecting the role of St. Peter as “substitute” for Christ (in Latin vicarius, corresponding in this sense to the Arabic khalīfah); if it had been so, this way of “veiling” the symbolism of the corner-stone would seem to show that it was felt to contain something particularly mysterious, and we shall see later that this is far from improbable.[5] However that may be, there is, in taking the two stones as identical, a simple logical impossibility which can be shown clearly by examining the texts already quoted: the “foundation stone” is the one first placed, right at the beginning of the work of constructing a building (and this is of course also why it is called the first stone)[6] how, then, could it possibly be rejected in the course of the same construction? For this to be possible the rejected stone would have to be the “corner-stone”-the stone for which as yet there is no place; and, as we shall see, no place can in fact be found for it until the moment of completing the whole building; it is in this way that it becomes the “head of the corner”.

In an article mentioned earlier[7] Ananda Coomaraswamy points out that the intention of the texts from St. Paul is clearly to represent Christ as that unique principle on which the whole structure of the Church depends, adding that “the principle of anything is neither a single part of it nor the sum of all the parts, but that by which all the parts achieve a unity,” The “foundation stone” might, in one sense, be called the “corner-stone” as is frequently done, because it may be positioned at an external or internal corner of the building;[8] but in that it is not unique, there being necessarily four corners to a building; and if one were to speak more particularly of the “first stone” it would then not in any way differ from any other corner foundation stone except by its situtation;[9] there would be no distinction of form or function between them as four equal supports. It might be possible to maintain that one or other of these four “corner-stones” in some way “reflected” the dominating principle of the building, but it could in no way be regarded as being that principle itself.[10] Besides, if this was really the case, one could not rationally use the term “the corner-stone”, there being in fact four of them. This “corner-stone” must therefore be something essentially different from the corner-stone in its ordinary usage as foundation stone and the two meanings have only their joint character in common as belonging to the same “building” symbolism.

Allusion has just been made to the shape of the “corner-stone”, this contains an important point since this stone has a peculiar, unique shape which makes it different from all others; not only can no place be found for it as the building progresses, but the builders themselves cannot envisage its final use; if they had understood, then clearly they would not have thrown the stone away but rather put it on one side until the end. But they ask each other “What is to be done with this stone?”, and, finding no satisfactory answer, they decide to “heave it over among the rubbish”, thinking it unusable.[11] The final destination of this stone could only be understood by a different category of builder, not involved at this stage, being one who has progressed from “the square to the compass”, the distinction being based on the geometrical figures for which these instruments are respectively used—the square and the circle—symbolizing in a general way the earth and the sky; here the square figure denotes the lower part of the building and the circle the upper part, which in this case would be a dome or vault.[12] In fact the “corner-stone” is really a “keystone”. Coomaraswamy says that in order to render the true meaning of the expression “is become the head of the corner” it should rather be translated “is become the keystone of the arch”, which is perfectly correct; thus this stone becomes genuinely unique, by both shape and position, within the whole building, as it must be in order to symbolize the principle upon which all depends. It is perhaps a little surprising that this representation of the principle is the last to be incorporated; but then it can be said that the whole building is constructed around this point, (as St. Paul expresses it in saying “in whom all the building fitly framed together groweth unto an holy temple in the Lord”) and it is in that building that final unity is achieved—yet another instance of that analogy, already frequently explained else-where, between “first” and “last”, “beginning” and “end”; the building represents manifestation in which the beginning, or principle, only appears as the final achievement; and it is precisely by virtue of this same analogy that the “first stone” or the “foundation stone” can be regarded as a “reflection” of the “last stone” which is the real “corner-stone”.

The equivocal nature of expressions such as “corner-stone” lies precisely in the possible different meanings of the words “corner” and “angle”. Coomaraswamy points out that in different languages words which mean “angle” are often related to others meaning “head” and “extremity”: in the Greek kephalé—“head” and in architecture “capital” (capitulum diminutive of caput) are only applicable to a summit, but akros (Sanskrit agra) can be used to indicate an extremity in any direction—in the case of a building the highest point, or any of the four corners (this last word being etymologically derived from the Greek gōnia—angle or corner)—even though it is preferably used for the highest point. Even more important, in dealing with texts on the “corner-stone” in the Judaeo-Christian tradition, is consideration of the Hebrew word meaning “corner”: the word is pinnah, and one finds the expressions eben pinnah, “corner-stone” and rosh pinnah, “head of the corner”. It is particularly remarkable, however, that in this context this same word pinnah, is also used to mean “chief”. One expression meaning “chief of the people” (pinnoth ha-am) istranslated literally in the Vulgate as angulos populorum.[13] A“chief” is etymologically a “head” (caput), and pinnah comes from a root pnê meaning “face”; the close relationship between the ideas of “head” and “face” is self-evident, and, moreover, the term “face” belongs to an extensive symbolism worthy of separate treatment.[14] Yet another association is that of the “point” (found in the Sanskrit agra, the Greek akros and the Latin acer and acies); we have already mentioned the symbolism of points in relation to arms and horns[15] and we have seen how it is associated with the idea of extremity, most particularly, however, in whatever involves a superior extremity—the highest point or summit. All these connections only serve to confirm what has been said of the situation of the “corner-stone” at the top of the building; even if there are indeed some other “corner-stones” in a more general sense, it is only this one which is really the corner-stone.

There are other interesting implications in the meaning of the Arabic word rukn—“angle” or “corner”: this word, because it indicates the extremities of a thing, and thus the most withdrawn and most hidden, (recondita and abscondita as one might say in Latin) sometimes takes on a meaning of “secret” or of “mystery” and in this respect its plural arkān is close to the Latin arcanum, which also has the same meaning and to which it has a striking resemblance; moreover, in the hermetic language, at any rate, the use of the word “arcane” was certainly directly influenced by the Arabic word in question.[16] Apart from this, rukn also has the meaning of base, or foundation, taking us back to “corner-stone” in its meaning of “foundation stone”. In alchemical terminology el-arkān, used without further qualifications, are the four elements or the material “bases” of our world, which are thus similar to the foundations of the four corners of a building, since it is upon them that the whole corporeal world (represented by the shape of the square) is constructed.[17] Thus we are once more returned to the symbolism here involved. In fact there are not only these four arkān or “basic” elements, but also a fifth rukn the fifth element or the “quintessence” (that is to say the ether, el-athir) this latter is not on the same level as the others, for it is not simply as a base as they are, but indeed the principle itself of the world,[18] it will thus be represented by the fifth angle or corner of the building—its summit; and this “fifth” which is in reality the “first” conforms appropriately to the designation of supreme angle, angle “par excellence” or the angle of angles (rukn el-arkān) because in it the multiplicity of the other angles is reduced to unity.[19] One may also note that the geometric figure obtained by joining these five corners is that of a pyramid on a quadrilateral base: the lateral lines emanate from the summit like rays, whilst the four ordinary elements, represented by the lower extremes of these lines proceed from the fifth and are derived from it; it is also for this reason, following the same lines, we have likened them to rays (and also by virtue of the solar character of the point of issue, in accordance with our earlier discussion of the “eye” of the dome) that the “corner-stone” at the summit is “reflected” in each of the “foundation stones” of the four corners of the base. To summarize, there is, in what has just been said, a very clear indication of the correlation between the symbolism of alchemy and that of architecture which is, moreover, explained by their common “cosmological” character; this latter important point will be returned to in dealing with other relationships of the same nature.

The “corner-stone”, in its sense of the “summit” stone is referred to in English as the keystone as capstone (sometimes spelled “capestone”) and as copestone (or coping stone); the first of these words is readily comprehensible for it corresponds exactly to the French clef de voute (or clef d’arc, literally the key of or to the vault or arch, the term being equally applicable to the stone forming the top of a vault as to the top of an arch) but the other two need a little more explanation. The “cap” in capstone is clearly the Latin caput meaning “head” leading us back to the description of this word as “head of the corner”; it is precisely this stone which “finishes” or “crowns” the building; it is also a capital, which is the same as “crown” to a column.[20] We mentioned “finishing” and that the two words “cap” and “chief” were in fact etymologically identical,[21] the capstone is thus the “chief” of the building or the “work”, and, by reason of its form, which demands special knowledge and skill for its shaping, it is also a chef-d’oeuvre in the craft-guild sense of this expression;[22] by it the building is completely finished, or in other words brought to its final “perfection”.[23]

As for the term “copestone”, the word “cope” carries the implication of “cover”: this is explained not only by the top part of the building being its “cover”, but also, more especially by the fact that this stone is so positioned as to cover the opening at the top, or the “eye” of the dome or vault, already mentioned.[24] It is thus, in this respect of a roof-plate, as Coomaraswamy points out, adding that the stone might be regarded as the upper terminal, or capital of the “axial pillar” (Sanskrit skambha, Greek stauros);[25] this pillar, as already remarked, cannot be materially represented in the structure of the building, but it is nevertheless an essential part of it, around which the whole is organized. Its character as the summit of the “axial pillar” present only “ideally”, is most strikingly shown in those cases where the keystone has a descending or “pendant” form going down into the interior of the building, with no visible support at its lower end,[26] the whole construction derives its principle from this pillar and all its different parts arrive finally at unity in its ridge pole at the top of this pillar which is the “keystone” or “head of the corner”.[27]

The real interpretation of the “corner-stone” as “summit-stone” seems to have been fairly well known in the Middle Ages as is shown in an illustration from Speculum Humanae Salvationis, described here.[28] This was a widely distributed work, there being several hundred manuscripts still in existence; in the illustration, two masons, each with a trowel in one hand, hold in the other the stone which they are preparing to position on the top of the building (it would seem to be a church tower, needing this one stone to complete the top)—there seems little doubt as to its significance. It may be noted with regard to this form that the stone acting as keystone, or some similar function depending on the exact structure of the building destined to be “crowned”, cannot, by reason merely of its shape, be positioned any way but upright as shown (in default of which it might clearly fall inside the building; thus it represents, in some sort, the “stone fallen from heaven”, an expression highly appropriate to Christ[29] , and recalls the stone of the Sangrael (the lapsit excillis of Wolfram d’Eschenbach, which can be interpreted as lapis ex coelis).[30] There is a further point to be considered. Erwin Panofski noted that the illustration shows the stone as diamond-shaped, (a further similarity with the Grail stone because this is also described as cut with facets); it is worth looking at this more closely, for even if the representation is a far from common one, it ties up with other areas of the complex symbolism of the “corner-stone” than those we have studied up to now and which are no less interesting for their ability to reveal links with the whole area of traditional symbolism.

However, before coming to this, there is a minor question to be elucidated: it was said that the “summit stone” may not be the “keystone” in every case, indeed is only so when the top part of the building is in the form of a dome. In other cases, with pointed roofs or those with tent-like shapes, there is no less a “last stone” positioned at the summit and in this respect it has the same function as the “keystone” and thus corresponds to it symbolically, even if not called by the same name, and this can equally be said of the “pryamidion” to which allusion has already been made. It must be understood that the symbolism of builders in the Middle Ages leans heavily on Judeo-Christian tradition and is specifically connected with the building of the Temple of Solomon as its “prototype”[31] and the consistent view that the “corner-stone” is really the “keystone”; furthermore, had it been possible for ordinary historical examination to be made of the form of Solomon’s Temple, it is quite certain that it would not have turned out to be a pyramid. These facts should be borne in mind when interpreting biblical texts concerned with the “corner-stone”.[32] The “pyramidion” the stone at the summit of a pyramid, is in no way a “keystone” but is none the less the “crown” of the building, reproducing in miniature the whole shape of it, as if the totality of the structure were synthesized in this one stone. The expression “head of the corner”, in the literal sense, fits it well as does the figurative meaning of the Hebrew name of the angle/corner to mean “chief”, especially as the pyramid, commencing with multiplicity at its base and coming gradually to unity at its apex, is often taken as a symbol of hierarchy. On the other hand, bearing in mind previous treatment of the summit and four corners of the base, in connection with the Arabic rukn it is possible to say that the pyramid shape is in some ways implicit within any architectural structure; the above-mentioned “solar” symbolism of this shape is to be found more particularly expressed in the “pyramidion”, as is clearly shown in a variety of architectural descriptions quoted by Coomaraswamy: the central point or summit corresponding to the sun itself, whilst the four faces (each bordered by two “rays” at the edges, defining the domain that it represents) have likewise secondary aspects of the sun, corresponding to the four cardinal points to which they are orientated. In spite of the foregoing, it is nevertheless true that the “pyramidion” is only a special case of the “corner-stone”, representing it only in one special traditional form peculiar to the ancient Egyptians; to fulfill the Judeo-Christian symbolism of the same stone, which belongs to a certainly very different traditional form, it lacks one vital characteristic, that of the “keystone”.

This being said, we may now turn back to the “corner-stone” as a diamond. In the article already referred to A. Coomaraswamy begins with a reference to the German word Eckstein which combines the meanings of “corner-stone” and “diamond”[33] which recalls the symbolic significance of the vajra, which we have already discussed several times. Generally, whatever stone or metal has been taken to be the hardest and brightest has become, in different traditions, “a symbol of indestructibility, invulnerability, stability, light and immortality”; these are qualities most often attributed to the diamond. The idea of indestructibility or indivisibility (closely associated and expressed in the same Sanskrit word akshara) is obviously a suitable one for the stone representing the single principle of the building, (true unity is essentially one and indivisible). The idea of “stability”, which in the architectural canon is properly applied to a pillar, is equally appropriate for the stone regarded as the capital of the “axial pillar”, itself symbolizing the “axis of the world”, and this, notably described by Plato as an “axis of diamond”, is also, moreover, a “pillar of light” (as symbolic of Agni and as a solar ray). For very good reason this last quality applies (eminently, one might say) to the “crowning” which represents the very source from whence, as a luminous ray, it issues forth.[34] In Hindu and Buddhist symbolism everything with a “central” or “axial” meaning is usually likened to a diamond (for example in expressions such as vajrasana—diamond throne) and it is easily seen that all these associations are part of a tradition which one can call truly universal.

Nor is this all: the diamond is held to be the “precious stone” par excellence; but this “precious stone” is also in itself a symbol of Christ, represented here by another of his symbols—the “corner-stone”, or if one so prefers, the two symbols are thus one and the same. One might also say that the stone, insofar as it represents a “finishing” or an “accomplishing”,[35] is in traditional Hindu language a cintamani, equivalent to the western alchemists’ expression “philosophers” stone”[36] , and it is highly significant in this connection, that Christian alchemists were wont to speak of Christ as the true “philosophers’ stone” no less than as the “corner-stone”.[37] Thus we return to the previous remarks on the meanings for the Arabic expression rukn el­arkān and the correspondence between architectural and alchemical symbolism.[38] To bring to a close this already long, but doubtless incomplete, essay, the subject being well-nigh inexhaustible, one further observation is of general significance. This architectural/alchemical correspondence is only a special case of the correspondence which exists equally, through often in much less obvious ways, between all sciences and all traditional arts, for they are in reality only different expressions and applications of the same primeval and universal truths.





NOTES

[1] Published in Etudes Traditionnelles, April/May 1940.
[2] Psalm 118: 22; St. Matthew 21:42; St. Mark 12:10; St. Luke 20:17.
[3] St. Matthew 16:18.
[4] Epistle to the Ephesians 2:20-22.
[5] The “substitution might also have been facilitated by the phonetic similarity between the Hebrew kephas, meaning stone or rock, and Greek kephalé (head); there is, however, no other connection between these words, and the foundation of a building obviously cannot be identified with its “head” or summit, this would be to turn the building upside-down; moreover, one may wonder if this “turning upside-down” has perhaps some symbolic relationship with the upside-down crucifixion of St. Peter.
[6] This stone must be positioned at the north-east corner of a building. It is worth noting here that in this symbolism of St. Peter a number of aspects or functions which have correspondingly different situations may be described as janitor, placed in the East, which is where one finds the entrance of a conventionally orientated church; moreover, St. Peter and St. Paul are also represented as twin pillars of the Church and even habitually represented, one with the keys and the other with the sword, in the attitude of two dvārapālas.
[7] Eckstein, in the journal Speculum, January 1939 (reviewed by R. Guénon in E. T. May 1939).
[8] We will be obliged, in this essay, frequently to refer to English “technical” terms because they derive originally from the working language of ancient masonry and have been specially preserved in the rituals of Royal Arch Masonry and in the accompanying ranks and degrees attached to this. There are no equivalent rituals in France.
[9] In the working ritual, this “first stone”, as we have said, is the one at the north-east corner. The stones for the other corners are successively to be positioned one by one following the course of the sun: south-east, then south-west, then north-west.
[10] This idea of “reflection” has clearly a connection with the “substitution” mentioned above.
[11] The expression “to heave over” is curious and not much used in current English. It seems to carry the meaning of “raise up” or “lift”, but in this context it is clearly “rejection” that we are concerned with.
[12] This distinction is, in other words, that between Square Masonry and Arch Masonry which, by their respective relations to earth and heaven, or with the part of the building they represent, correspond here with the “lesser mysteries” and the “greater mysteries”.
[13] Samuel 14:38. The Greek of the Septuagint similarly uses gōnia here.
[14] Cf. A. M. Hocart, Les Castes, pp.151-154 regarding the expression “faces of the earth” used in the Fiji Islands for chieftains,—the Greek word karai, in the early centuries of Christianity, was used for the five “faces” or “heads” of the church”—the five principal patriarchs whose initials made up the word thus: Constantinople, Alexandria, Rome, Antioch, Jerusalem.
[15] One notes that the English word “corner” is clearly derived from “corne”.
[16] In this sense there not merely four “corner-stones” at the base, since they appear at other levels of construction and all these stones have an ordinary rectilinear and rectangular shape (in other words cut “on the square”, the word square meaning either a square shape or a set-square) contrary to the case of the unique keystone.
[17] It might be interesting to research the possible direct etymological connection between the Arabic and Latin words even in the ancient usage of the latter, (for example, in the disciplina arcani of the early Christians), or whether it arose only by “conveyance” in much later alchemical usage.
[18] This similarity between the elements and the four corners of a square is naturally related to the correspondence between these same elements and the four cardinal points.
[19] It would be on the same plan (in its central point) if this plan were taken to represent the whole state of being; but here that is not the case for it is the totality of the building which is an image of the world—whilst on this point it is noted that the horizontal projection of the Pyramid, discussed a little earlier, constitutes a square with diagonals in which the sides follow and meet in the centre of the square itself.
[20] In the sense of “mystery”, noted above, rukn el-arkān isequivalent to sirr el-asrār which is represented, as explained elsewhere, by the topmost point of the letter alif; the alif itself representing the “axis of the world”; this, as we shall soon better appreciate, corresponds exactly to the position of the keystone.
[21] The term “crowning” is close to the description of the crown of the head, by the same symbolic correlation, pointed out earlier, just as the “eye” of the dome is similar to the Brahma-randhra; from other sources it is known that the crown and horns are essentially expressions of elevation. One might note here, appropriately, that the oath of office of the Royal Arch contains an allusion to the crown of the skull, which suggests a relationship between the opening of this (as in rites of posthumous trepanning) and the removing of the keystone. For the rest, in general terms, the so-called “penalties” expressed in the oaths of different masonic ranks, and the corresponding signs, are really related to various subtle centers of the human body.
[22] In the meaning of the French achever, or the old French mener à chef, the idea of “head” is associated with that of “end” (Translator, cf. English “bring to a head”) which corresponds well with the situation of the “corner-stone” as at once “summit-stone” and “last” or final stone of the building. One should also mention yet another term derived from chef: the chevet of a church is its “head”, that is to say the eastern end where the apse is situated, the semi-circular shape of which corresponds in the horizontal plan to the dome or cupola in the vertical elevation, as already mentioned.
[23] The word œvre, work, is used both in architecture and alchemy, nor is this analogy without reason: in architecture the finishing or final achievement of the work is the corner-stone; in alchemy it is the philosophers’ stone.
[24] It should be noted that in certain masonic rites the ranks which correspond more or less exactly with the upper part of the building, as dealt with here (more or less exactly because there are always some discrepancies) are precisely described by the name of “ranks of perfection”. Elsewhere the word “exaltation”, which indicates accession to the Royal Arch, can be taken to allude to the elevated position of the keystone.
[25] The expression used for the positioning of this stone is “to bring forth the copestone”, the meaning is obscure at first sight, “bring forth” literally means “to produce” (in the Latin meaning of producere) or “bring to light”; because the stone has already been cast aside in the course of building, there can be no question on the final day of completion of its “production” in the sense of a “construction”, but because it has been buried (heaved over among the rubbish) it must now be recovered to be brought to light at the top of the building to become the “head of the corner”, thus to “bring forth” is here the opposite of the “heave over”.
[26] Stauros also means “cross” and it is well known that in Christian symbolism the cross is likened to the “axis of the world”. Coomaraswamy compares this word with the Sanskrit sthāvara, “firm” or “stable” which is appropriate for a pillar and, besides, agrees exactly with the meaning of “stability” given to the joining of the names of the two columns of the Temple of Solomon.
[27] It is this summit of the “axial pillar” which, as we have noted, corresponds to the topmost point of the alif in literal Arabic symbolism. We may also recall that, regarding the words “keystone” and clef de voûte, the symbol of the key also has an “axial” significance.
[28] Coomaraswamy recalls the symbolic identity of the roof (more especially in vault form) and the parasol. We would also add here that the Chinese symbol for the “Great Extreme” (T’ai-chi) means literally a ridge or roof; it is, indeed, a “roof of the world”.
[29] Manuscrit de Munich, elm. 146, fol. 35 “Lutz et Perdrizet, II, pl. 64.): the photograph was passed on to us by Coomaraswamy. It was reproduced in Art Bulletin XVIII, p. 450 and fig. 20, by Erwin Panofski, who thought this illustration nearest to the prototype and who, in this connection, treats of lapis in caput anguli as a keystone. It could also be said in accordance with previous explanations, that this drawing represents the “bringing forth of the copestone”.
[30] There is a parallel between the “stone falling from heaven” and the “bread descending from heaven” for there are important symbolic associations between bread and stone, though this is to stray beyond the scope of the present subject: “descending from heaven” always naturally represents the avatarana.
[31] Cf. also the symbolic stone in l’Estoile Internelle, discussed by Charbonneau-Lassay, which, like the emerald of the Grail, is a faceted stone; this stone placed in the cup exactly corresponds to the “jewel in the lotus” (mani padme) in Mahayana Buddhism.
[32] All branches of the craft-guilds maintain belief in the “legends” of craft-guild origin, no less that the “survivals” of ancient working masonry which we have considered here.
[33] There cannot be the slightest question, as some have suggested, of an allusion to an incident during the construction of the Great Pyramid, as a result of which it remained unfinished—in any case a very dubious hypothesis, and likely to remain an historical mystery; also this “failure of achievement” would run directly counter to the symbolism by which the rejected stone finally takes its place as the “head of the corner”.
[34] Stoudt, Consider the lilies how they grow, in connection with the meaning of an ornamental diamond motif, explained in his writings the significance of Christ as being the Eckstein—The double meaning of this word is probably explained from the etymological standpoint by being understood both as “corner-stone” and “stone with corners” or facets; such an explanation naturally in no way diminishes the value of the symbolic comparison shown by the joining of these two meanings in one word.
[35] Normally the uncut diamond has eight angles, and the sacrificial post (yûpa) was made with eight angles (ashtashri) to represent the vajra (which is taken here equally in its other meaning as “thunder”); the Pāli word attansa, literally “having eight angles”, means both “diamond” and “pillar”.
[36] From a “constructive” point of view it is “perfection”, the fulfillment of a plan drawn by the architect; from the alchemical viewpoint it is “perfection” or the ultimate aim of the Great work, and there is an exact correspondence between the two.
[37] There is nothing more precious than the diamond among stones and gold among metals and they are both equally “luminous” and solar in character; but the diamond as the philosophers’ stone, to which it is likened here, is regarded as even more precious than gold.
[38] The symbolism of the “corner-stone” is, for example, especially mentioned in several passages of Robert Fludd’s hermetic works, quoted by A. E. Waite in The Secret Tradition in Freemasonry, pp. 27-28; but it is necessary to remark that these texts seem to perpetuate its confusion with the “foundation stone” referred to earlier and that which the author calls the “corner-stone” in several places in the same book, which hardly elucidates the subject but rather adds to the confusion.

Source: Studies in Comparative Religion, Vol. 14, Nos. 3 & 4. (Summer-Autumn, 1980). 
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