"Architecture is two things: it is service and it is art. It has to work and it has to be seen to work. It is building and an image of building; structure and an image of structure. An architect is thus both a builder and an image-maker, and styles in architecture is just a way of building codified in imagistic form. In simply organised societies - communities with unitary cultures - there is no radical choice of image. Style is still a vernacular medium, not a product of aesthetic preference. But between the disintegration of the classical tradition in the second half of the eighteenth century, and the rise of the Modern Movement in the first half of the twentieth century, architects were faced with a choice - in many cases a multiple choice - between alternative images, alternative codes, alternative systems of design, alternative styles. That choice I have called The Dilemma of Style. [...]
In brief the stylistic dilemma was a product first of the Renaissance (which gave us the idea of individual style), and then of Romanticism (which gave us the idea of a multiplicity of styles). [...]
It was in the area of romantic landscape that the idea of appropriate form, that is a style appropriate to a particular context, first came to fruition. Of course the idea had a long history. Vitruvius endowed the different classical orders with distinct characters - masculine Doric, matronly Ionic, and so on - establishing a classical tradition of decorum, or manner, and this variation and stylistic differentiation; ideas which in turn were developed in eighteenth-century France. J.-F. Blondel explained the appropriate use of style as a kind of 'colouration', 'the poetry of architecture'. 'In a word', he suggests, 'style... enables the architec to create a sacred genre, a heroic one, a pastoral one'. Ledoux took such ideas of stylistic expression a good deal further, designing buildings such as his notorious phallic-shaped brothel, or his barrel-shaped house for a cooper or barrel-maker, which are themselves three-dimensional metaphors. Architecture thus becomes a symbolic language.
In the early eighteen century - the cultural watershed when nature replaced religion as the motive force for creative artists - the cult of styles had become rooted in the soil of the Romantic landscape. But it was not until the early nineteenth century that choice developed into conflict. [...] Buildings were now pictorially conceived as memories in three dimensions [...].
The habit of regarding buildings as scenery - as aggregates of separate visual units - encouraged not only irregular skylines and asymmetrical plans, but triangular, hexagonal, and octagonal features, eyecarcher and all manner of follies [...]. Picturesque thinking was certainly an encouragement to drawing-board architecture: designing a house from the outside inwards, rather than from the outside outwards - a process of design ideal for landscape features. Carter's triangular fort is reciprocally picturesque: a building designed to be looked at as well as looked from; an example of scenographic design, based on the multiplications of points of vision."
Van Eck, Caroline; McAllister, James; Van de Vall, Renée (eds.) (1995) The question of style in philosophy and the arts. Cambridge University Press, Cambridge.