4. 'Venerable Nâgasena, this too was said by the Blessed One:
"This is an impossibility, an occurrence for which there can be no cause, that in one world two Arahat Buddhas supreme should arise at one and the same time --such a thing can in no wise be 1."
'But, Nâgasena, when they are preaching, all the Tathâgatas preach (the Doctrine as to) the thirty-seven constituent elements of insight 2; when they are talking, it is of the Four Noble Truths that they talk; when they are instructing, it is in the three Trainings 3 that they instruct; when they are teaching, it is the practice of zeal 4 that they teach. If, Nâgasena, the preaching of all the Tathâgatas is one, and their talk of the same thing, and their training the same, and their teaching one, why then should not two Tathâgatas arise at the same time? Already by the appearance of one Buddha has this world become flooded with light. If there should be a second Buddha the world would be still more illuminated by the glory of them both. When they were exhorting two Tathâgatas would exhort at ease; when they were instructing two Tathâgatas would instruct at ease. Tell me the reason of this, that I may put away my doubt.'
5. 'This world system, O king, is a one-Buddha-supporting world; that is, it can bear the virtue of only a single Tathâgata. If a second Tathâgata were to arise the world could not bear him, it would shake and tremble, it would bend, this way and that, it would disperse, scatter into pieces, dissolve, be utterly destroyed. just as a boat, O king, might be able to carry one passenger across. Then, when one man had got on board, it would be well trimmed and able to bear his weight 1. But if a second man were to come like to the first in age and caste and strength and size and stoutness of body and build of frame, and he too should get on board the boat--would that boat be able, O king, to carry them both?
'Certainly not, Sir! it would shake and tremble; it would bend, this way and that; it would break into pieces, be shattered, dissolved, and utterly destroyed; it would sink into the waves.'
'Just so, O king, with this world, if a second Tathâgata were to appear. Or suppose, O king, that a man  had eaten as much food as he wanted, even so that he had filled himself with nourishment up to the throat, and he--thus satiated 2, regaled, filled with good cheer, with no room left for more, drowsy and stiff as a stick one cannot bend--were again to eat as much food as he had eaten before--would such a man, O king, then be at ease?'
'Certainly not, Sir! If he were to eat again, but once more, he would die.'
'Well, no more could this world bear a second Tathâgata, than that man could bear a second meal.'
6. 'But how is that, Nâgasena? Would the earth tremble at a too great weight of goodness?'
'Suppose, O king, there were two carts quite filled with precious things up to the top 1, and people were to take the things from the one cart and pile them up on the other, would that one be able to carry the weight of both?'
'Certainly not, Sir! The nave of its wheels would split, and the spokes would break, and the circumference would fall to pieces, and the axle-tree would break in twain 2.'
'But how is that, O king? Would the cart come to pieces owing to the too great weight of goods?'
'Yes, it would.'
7. 'Well, just so, O king, would the earth tremble owing to the too great weight of goodness. But that argument has been adduced to make the power of the Buddhas known 3. Hear another fitting reason why two Buddhas could not appear at the same
time. If, O king, two Buddhas were to arise together, then would disputes arise between their followers, and at the words: "Your Buddha, our Buddha," they would divide off into two parties--just as would the followers of two rival powerful ministers of state. This is the other  reason, O king, why two Buddhas could not appear at the same time.
8. 'Hear a further reason, O king, why two Buddhas could not appear at the same time. If that were so, then the passage (of Scripture) that the Buddha is the chief would become false, and the passage that the Buddha takes precedence of all would become false, and the passage that the Buddha is the best of all would become false. And so all those passages where the Buddha is said to be the most excellent, the most exalted, the highest of all, the peerless one, without an equal, the matchless one, who hath neither counterpart nor rival--all would be proved false. Accept this reason too as in truth a reason why two Buddhas cannot arise at once.
9. 'But besides that, O king, this is a natural characteristic of the Buddhas, the Blessed Ones, that one Buddha only should arise in the world. And why? By reason of the greatness of the virtue of the all-knowing Buddhas. Of other things also, whatever is mighty in the world is singular. The broad earth is great, O king, and it is only one. The ocean is mighty, and it is only one. Sineru, the king of the mountains, is great; and it is only one. Space is mighty, and it is only one. Sakka (the king of the gods) is great, and he is only one. Mara (the Evil One, Death) is great, and he is only one. Mahâ-Brahmâ is mighty, and he is only one.
[paragraph continues] A Tathâgata, an Arahat Buddha supreme, is great, and he is alone in the world. Wherever any one of these spring up, then there is no room for a second. And therefore, O king, is it that only one Tathâgata, an Arahat Buddha supreme, can appear at one time in the world.'
'Well has the puzzle, Nâgasena, been discussed by simile adduced and reason given. Even an unintelligent man on hearing this would be satisfied; how much rather one great in wisdom as myself. Very good, Nâgasena! That is so, and I accept it as you say.
[Here ends the dilemma as to why there should be only one Buddha at a time in the world.]