Philosophers and psychologists have contributed substantially in the theory of art and aesthetics. The great critics of art are not artists. Creation and perception of art are two different processes. Images of the unconscious mind play a vital role in decision-making. It is very interesting to know what well-known psychologists have to say about visual perception and the formation of visual images in our mind. Students of architecture should know the difference between a design and a work of art. The architect is basically a designer rather than an artist. The ability to analyse and criticise works of art and architecture becomes an additional qualification for the professional architect. Precise use of terminologies and vocabulary is necessary. The words like rhythmic spaces, monumental proportions, dynamic colours, focal points, radiating lines and so on, are often used in architectural journalism. The theoretical discussion in this section is further divided into four subsections viz., art in architecture, visual perception, visual studies and core theory. It is expected that visual designers should have a strong foundation of the knowledge of art while they experiment.