 In Book of Letters I,88–90 Fârâbî describes not only the different senses of “being [mawjûd]”, but also the corresponding senses of “existence [wujûd]”, i.e., that through which a mawjûd in each sense is mawjûd. As we have already seen, “the existence [wujûd] of what is true is a certain relation which thoughts have to something outside the soul” (p.117,4–5). The existence [wujûd] of something which is a being [mawjûd] in the sense in which being is divided into the categories will just be the category under which that thing falls, which licenses calling it a being. Fârâbî’s treatment of the existence [wujûd] of something which is a being [mawjûd] in the sense of being circumscribed by some quiddity outside the soul depends on whether it is a complex (divisible) or a simple (indivisible) quiddity.