The image of Occasio is taken from a work by famous Czech philosopher and pedagogue Johan Amos Comenius (Moravia 1592-Amsterdam 1670), the Orbis sensualium pictus (1658). The book contains pictures with text in Latin and the vernacular, and was intended for teaching. Occasio is the Opportunity we must seize before it flies away and vanishes: "Occasioni (quae, fronte capillata sed vertice calva, ad hoc alata facile elabitur) attendit captatque eam", or, " She watches Opportunity (which, having a forelock but being bald at the back of its head and being winged, escapes easily) and seizes it." "She" is Prudentia, looking at the past with one of her two faces and at the future with the other. Occasio was chosen by Tjebbe van Tijen as an emblem appropriate for a project aiming to archive such volatile materials as Internet documents. An other image of Occasio can be found at Alciato Emblem 122 (Latin) from the 1621 edition of Andrea Alciato's Book of Emblems. See also Prudentia, from Comenius Orbis Sensualium Pictus at the Universidad Nacional de Educación a Distancia.