Around the 11th century, Abd al-Qahir al-Jurjani wrote a treatise entitled The Secrets of Eloquence (Asrar al-Balagha). It has been noted by modern scholars (namely Kamal Abu Deeb) that his approach to poetics is a psychological one. That is, he is concerned with the emotional impact a poetic statement has on the listener. Not much attention has been given to the nature and mechanisms of this emotional effect, however. I argue that upon closer analysis it becomes clear that the pleasure one experiences when listening to poetry is the result of a process of discovery. This is particularly evident in his discussion of tashbih (simile), which - according to al-Jurjani - forms one of the pillars of poetic speech and constitutes the basis on which metaphor is built. al-Jurjani argues that when two things are compared to each other, the listener is launched into a search for the similarity between the two things compared. The search for and the discovery of this similarity is what causes pleasure and wonder in the listener. In order for a comparison to allow for an experience of discovery, however, the original meaning being described has to be (or be made) strange or obscure. Furthermore, he argues that the more effort is required to discover the similarity, the more rewarding it is. al-Jurjani goes on to detail how discovery in a comparison can be made more arduous. As a result, he argues that the stranger and more farfetched the comparison, the greater the resulting pleasure. This is particularly significant in a critical tradition that generally regarded strangeness and obscurity as undesirable qualities in poetry and one that judged poetry based on its straightforwardness and closeness to reality. In this paper, I will present my analysis of al-Jurjani’s theory of simile and I will end by briefly describing its development in later authors that were very much influenced by him, namely al-Sakkaki and al-Khatib al-Qazwini.