Traditionally, architectural creation requires sketches, drawings or models made in the design phase prior to construction. This study considers such media as representational media for architectural design. In De re aedificatoria, Alberti presents his own architectural theory, and, especially in Bk. 2 Ch. 1, he discusses drawings or models in architectural design. According to other studies, in Bk. Ch., Alberti might implicitly prohibit architects from using the linear perspective. However, the current author’s previous papers have confirmed that, for Alberti, the linear perspective was a concept to be used, not only by painters, but also by architects and sculptors. However, a question remains unanswered: ‘In Alberti’s view, in what way was the linear perspective most useful for the creation of plastic arts, particularly architectural design?’

 This paper draws its clarification via the following two-stage methodology. First, the author examines Alberti’s recognition of the linear perspective as basic technology in plastic arts’ creation – summarising his discussions of the linear perspective. Second, he investigates the fundamental usefulness of the linear perspective in Alberti’s conception of architectural design – referencing his thoughts as delineated in the first stage.

 According to the findings from the first sage, for Alberti, the linear perspective is a drawing method founded on the logic of the visual pyramid as the principle of painting. Based on this logic, he presents three painting methods: line drawing, composition and colouring. Among the three, Alberti ranks line drawing as the base of painting, which all plastic artists must study as their own technology. In his conception, the linear perspective is the technology that includes the line drawing – the basic technology for all plastic arts. Thus, Alberti considers the linear perspective to be the basic technology for plastic arts’ creation.

 The second stage reveals that Alberti believes the linear perspective to be the technology dealing with outlines of various bodies. According to the current author’s previous papers, Alberti states that such outlines are potential lines, essentially making the external forms of the bodies. He perceives those outlines to actually be the lines as representational media, assumed as basic elements in the nature of the object. He also argues that all the plastic artists must imitate nature to create works. That is, for him, the outlines are the imaginary lines shaping the forms of the works in the plastic artists’ minds. However, according to Alberti’s experiences, plastic artists cannot accurately design their works in their minds only. For accurate design, they must examine the outlines in more concrete loci. Therefore, he gives to the linear perspective the role of reproducing the outlines from artists’ minds on certain picture-planes, for the first time, before the works are realised. Thus, to Alberti, the linear perspective in the creation of plastic arts, including architectural design, is most useful for exactly comprehending, all parts of the works, specifically the outlines shaping their forms.

 Through the above findings, the essential significance of the linear perspective in architectural design, from the perspective of Leon Battista Alberti, has been clarified.