 With his theory of distribution in place, Buridan turns to the syllogisms, and we see now that in order for a combination of premises to be acceptable, the middle terms must be distributed — otherwise we will not have a formally acceptable consequence. Buridan approaches the problem in combinatorial fashion. Given the four sentences and two possible positions for each we get 16 possible combinations. Some of these can be ruled out immediately based on the rules for distribution. A combination with only negative premises will not work at all; hence EE, EO, OE, and OO must be rejected. II has both middle terms undistributed and can thus be rejected. In the first figure, IA, OA, and OI have an undistributed middle. The other eight are accepted. In the second figure, we see that AA, AI, and IA must be rejected because of an undistributed middle. The other eight are accepted. In the third figure, IO and OI have an undistributed middle but the remaining nine combinations are accepted.