Sebastiano Serlio’s Libro Estraordinario (Lyons, 1551, also 1558 and 1560) contrasts thirty rustic gateways with twenty ‘delicate’ ones. In a well-known passage, Serlio describes how he came to conceive them:
‘… finding myself continually in this solitude of Fontainebleau, where there are more beasts than there are men, and having brought a long task of mine to conclusion, the desire came into my mind to form in a visible design several gateways in the Rustic style, but which were mixed with different Orders, that is, Tuscan, Doric, Ionic, Corinthian and Composite. And this was not without reason, because many times I saw and heard people looking at and praising the gateway of the Very Reverend and Exceedingly Illustrious Cardinal of Ferrara [of the Hotel du Grande Ferrare; the gate still stands, Fig. 1.] … and many wanted a copy of it so as to make use of it for themselves. From this sprang the idea (as I said above) of beginning such a task. [The first design is the portal of the Grande Ferrare, Fig. 2] And I advanced so far as to make a total of XXX, almost carried away by an architectural frenzy [furore architettonico]. Nor was this sufficient—sensing as I did that my mind abounded in new fantasies—hence I decided to make up XX of delicate work, also of different Orders, so as to satisfy the many desires of men and for the common benefit of this fine Kingdom of France (which has so great an interest in architecture) but also for the benefit of all inhabited countries …’
In a rather curious analogy, John Onians observes that:
‘Just as the Pantheon makes ugly people look beautiful for the short time they are in it, the environment of Fontainebleau makes Serlio have a fit of “furore architettonico” until he gets rid of it by exhausting himself in a bout of creativity’.
The process described by Serlio is one of the great statements of artistic inspiration as a non-rational process, driven by an uncontrollable creative urge. In antiquity this was largely confined to poets, who would be possessed of the furor poeticus, which came from the gods, especially Apollo, the Muses and Orpheus. It came easily to musicians as well as poets (in antiquity they were the same thing), as in the anecdote about Mozart folding and refolding his napkin in ever more complicated patterns as new musical ideas flowed through his head.
The physical labour involved in most visual art production—apart from napkin folding—tended to deny such inspiration to artists, but drawing could be almost as responsive to fleeting creative ideas as speech. Leonardo da Vinci was perhaps the first pictorial artist capable of a creative frenzy through drawing, especially with the rapid pen sketch of a pictorial idea, the primo pensiero (Fig. 3). Serlio was evidently heir to this, and the actual creative frenzy would perhaps have been first expressed in rapidly executed sketches. Or would it? Could he have maintained his initial creative frenzy in drawings almost as finished as the woodcuts and engravings made from them? There is a manuscript in Augsburg of these designs, probably pre-dating the final engraved designs, but these are finished drawings, and not the first idea. But would the initial ideas have developed on the drawing board with ruler, or freehand in a sketchbook? Certainly when Domenichino came to play around with sketches for a church façade, he used the painter’s primo pensiero technique (Fig. 4). But would Serlio have done so?
This is indeed architecture as music. Within the strict results of the gateway form, and a relatively limited vocabulary of forms, Serlio could play numerous variations on the garden portal theme.
The first thirty designs (Fig. 5 shows one of the best, no. XXIX) were followed by twenty ‘delicate’ gateways (Fig. 6). Onians discerns an opposition here between the first thirty, which are ‘extravagant irrational designs’ while ‘the delicate ones are relatively rational and correct’. He also develops the point that for Serlio the underlying rationality of the bizarre designs could be revealed by removing the rustication, so that it was like a civilised city gentleman adopting rustic trappings when going to the country without actually being a rustic.
It is interesting that these are oppositions between two sets of designs. Serlio makes no attempt to show the front and back of the same gateway. This is true of most garden gateways, which tend to be of little interest on the inside: they are always oriented to the street. Even a garden gate in an expressive Serlian manner, like the grotesque gate to the walled garden at Castle Howard by Vanbrugh (Fig. 7), focuses on the outward face; the interior face has little to say (Fig. 8).
Town gates, by contrast traditionally have two faces, one for the wild outlands, the other for the civilized city within. This goes back to the Emperor Trajan, who ‘presented a rough Tuscan portal to the barbarians outside the frontier and a soft Corinthian portal to the citizens inside in an expression of his different attitudes to the different populations.’ Giacomo del Duca’s Porta S. Giovanni presented a nondescript face to the city (Fig. 9) but an aggressively rusticated one to the countryside (Fig. 10). But it was rarely always that simple, and the scenographic view from the city side prevailed in two important instances. Michelangelo’s Porta Pia presented a scenographic structure visible for miles down the Porta Pia (Fig. 11), but the exterior was unfinished and nondescript (Fig. 12). The sixteenth-century country façade of the Porta del Popolo was a highly civilised ‘porta delicata’ and dependent on the Orders (Fig. 13); while the interior (partly visible on the exterior) was another scenographic spectacle, this time by Bernini (Fig. 14).
Should a garden gate be likewise two-faced? A case can be made for it. The street face needs to be hostile and defensive, given the grim world outside of trucks and sticky-beaks cruising past in the 4WDs—modern versions of the wild beasts of Serlio’s Forest of Fontainebleau. The inside face could therefore be an assertive contrast: soft, erotic and romantic.
Such an approach competes with a Neoclassical conception of such a gateway, which would model itself on a Roman Triumphal arch like the Arch of Titus, which have two matching facades. Such a gateway is primarily an assertion of it its antiqueness. This is something to be avoided.
While many have borrowed from Serlio, a difficulty with Serlio’s furor architettonico is that its meaning lies largely in the multiplicity of the resulting inventions. The point of the Libro estraordinario, after all, is that it is a book. A single gate, by its nature, cannot express a furor architettonico, although it can be bizarre, delicate, or have some other such property.
It therefore makes sense to conceive of a garden gate as being like a town gate: speaking in both directions, to the hostile outer world, and to the intimate private world.
A garden face may be ‘delicate’, following Serlio, or relate more literally to the vegetation found within the garden—espaliered camellias and so forth—suggesting a model where such organic forms have a place, such as the Rococo or even Art Nouveau. The street face has more readily available models—almost all those discussed here—and demands to imitate rusticated stone, the primal expression of rustic defensiveness. Yet cursive forms need somehow to be made architectonic.
 Onians, 2006: John Onians, ‘Serlio and the History of Architecture, in Art, Culture and Nature. From Art History to World Art Studies, London, The Pindar Press, 2006, chapter XVII, pp. 358–376, see p. 372.
 Leonardo da Vinci, Study of the Madonna and Child with a Cat, c. 1478; Milan, Italy. Ink on paper, 19.9 x 28.1 cm. London, British Museum.
 Staats- Stadtbibliothek of Augsburg, 2.o Cod. 496. See Johannes Erichsen, ‘L’Extraordinario Libro di Architettura. Note su un manoscritto inedito’, in Christof Thoenes (ed.), Sebastiano Serlio: Sesto Seminario Internazionale di Storia dell’Architettura ; Vicenza, 31 agosto – 4 settembre 1987, Milan, Electa, 1989, pp. 190–195.
 Onians, Bearers of Meaning, p. 280.
 Onians, Bearers of Meaning, pp. 281–82.
 (Onians, 2006, p. 372, citing Serlio, Book vii, Staatsbibliothek, Munich, cod. Icon. 190, fols 19v and 20r.) Not sure if this is in the printed edition.