The bullet of futile life, which is part of the multilingual medieval novel Barlaão and Josafat, conceals a unique interpretative approach, in terms of symbolism, of an ancient and intercultural mythological symbol, that of unicórnium. An initial examination of the cultural environment — textual and iconographic — of the appearance of unicórnium suggests that the symbolic substance of this animal pattern has been shaped by notions derived from the high virtues of the Christian ideological system (e.g. virginity, purity and salvation). However, the parabolic narrative of futile life reveals another aspect. This is the cruel internal power that leads the man to the wrong choice, preventing him from finding the right spiritual path to save after his physical death in the shuttle world in which he lives temporarily. Probably, the beauty of unicornium now symbolises something that is no longer so pure. Indeed, the history of useful life has become one of the most common iconographic themes of monumental Christian paint, including the presence of unicórnium, which at the same time raises reasonable concerns and the need for adequate explanations. Thus, by means of a list of relevant examples of monumental and miniature art, we will seek to identify the beginning of the two aspects of this old symbol, with an emphasis on the parbola studied, offering a new perspective on the semi-optical analysis of antiquity during the Middle Ages.