The division between Quattrocento and Cinquecento is sometimes somewhat arbitrary as it is impossible to establish an exact date for the start of the Renaissance. Many Renaissance artists participated in both periods, which correspond to the 15th and 16th centuries respectively. The same ideas and painters were present in both centuries, although it is possible to distinguish two different generations of artists and each period has a predominant centre. The nucleus of power during the Quattrocento was clearly [Medici#PERSONAS#12] Florence, whereas in the Cinquecento Papal Rome played the central role. As we have mentioned, the pictorial precedents of the Trecento determined the qualitative advances of the Quattrocento. Giotto's frescos and Cimabue's panels announced the coming revolution. Architecture was the starting point for this artistic transformation and in intellectual circles voices reclaiming a revaluation of artistic activity had begun to make themselves heard. Italian architecture had always been more closely adapted to human conceptions and was a long way from the theological spirituality of the European cathedrals. This sense of humanism and of breaking with the established order was best summed up by Bruneschelli in a work that can be considered a genuine statement of intent: the cupola of Santa Maria del Fiore, Florence cathedral. Bruneschelli used the latest techniques to design a cupola of an unprecedented size and with such pure lines that its beauty was extraordinary. At the same time he separated himself from the physical construction process, establishing the idea of the creator versus the constructor. Furthermore, he placed his creation in a place where it would have the greatest social impact: in the centre of the wealthy Florentine republic, the crossing point for all the commercial routes and economic operations of the Christian world. As a result, the entire world could contemplate the novelty. The repercussions were immediate and the discipline of sculpture also received a push towards the exercise of Reason over the image. Gothic fullness and solemnity were abandoned in favour of a desire for beauty and perfection. Sculpture had its own public manifesto in Ghiberti's Gates of Paradise (Florence Baptistery door). The achievements of both architecture and sculpture reached painting. The systemisation of construction methods required enormous scientific effort. Mathematics, physics and geometry were the main tools in the construction of new buildings. Painting adopted architecture's hypotheses and through them obtained one of its defining features: linear perspective. According to this system objects in the distance appear smaller than those close to the spectator. It consisted of abstracting both the gaze and the position of the object being represented from a unique point, which supposes an ideal view of the object from one eye, and that the object is centred from an average height. It was a purely mental exercise that aimed to create the illusion of three dimensional paintings, instead of the two dimensions of Romanesque and Gothic art. This three dimensional quality was meant to create a realistic image; as if a painting were a window that opened out onto the world. There was an instant revolution. Masaccio, a young painter in fashion at the time, did a pictorial manifesto in The Trinity, a fresco that pretends to pierce the wall depicted in the painting so that the eye appears to be looking into a Renaissance chapel which contains a life-size representation of the mystery of the three divine forces. The scandal caused by the image can only be compared to that of the first cubist paintings, and those of the 20th century avant-guard in general. The 15th century Florentines had never been forced to "read" such a complex image before and they found it difficult to learn the new language. Other concerns applied to painting were also born of this thirst for scientific knowledge. For example, the laws of optics regularised the hierarchy of objects represented in the distance, making them smaller and less well defined. For this it was essential to apply the golden section (1.61803), which was considered the rule to achieve harmonious proportions. It became necessary for a painter to study various branches of knowledge so that he could depict stories and their characters accurately. For a correct representation of the human form they studied anatomy and physiology. The notes with which early scientists illustrated their discoveries are difficult to separate from the artistic sphere. Artists also had to study mythology, classics and theology to represent scenes, clothing and settings appropriately. Three dimensional representation was reinforced in a number of ways: figures were not depicted against a flat, neutral background but rather against a landscape or interior. This meant that not only did the actual volume of the figure establish the depth, but so did the fact that they were moving against an aerial space. The tonal ranges and chromatic shading of the Trecento contributed to the introduction of effects of mass, volume and weight in the figures. All these ideas were accompanied by intense theoretical production: the artists themselves and the nobles who patronised them wrote treaties and manuals that explained the innovations so that they could circulate more easily. The visual world was ordered both in practice and in theory, relating it even more closely to the scientific world. On the whole, the subject matter of this new art continued to be religious, with three objectives: increasing the effectiveness of preaching, obtaining an emotional response from the faithful, and reminding believers of the dogma through images. However, there was also a surge in secular painting; on one hand, the portrait emerged to depict the patrons of the arts and the representatives of modern and ancient knowledge. On the other hand, the emergence of Florentine Neo-Platonism opened the door to the portrayal of pagan images, adapted to Christianity. Astrology, cabbala and Christian morality were studied without any type of conflict existing. The force of this knowledge of oriental origin was provoked by the fall of Constantinople, which led to the fleeing of many Greek and Byzantine intellectuals to Christian territory. Many figures from this period are vital to the history of painting: as well as from Massaccio, Paolo Ucello, Piero della Francesca, Andrea del Castagno and others formed the most radical group among the young painters of the time. With a more middle-ground posture, trying to combine modernity with the tastes of a conservative public, were the figures of Fra Angelico, in his The Annunciation, and Filippo Lippi, amongst others. The repercussions of the Quattrocento on the [Spanish#ESTILOS#2] and French Renaissances were shaped by each nation's own special characteristics, which were very closely related to the preceding Gothic period and the powerful influence of Flemish painting being developed parallel to the Early Renaissance.