Is the Western Land of Bliss within the Three Realms?

To understand this question, one must first consider three questions: What are the three realms? What are the characteristics of each of the three realms? What is outside the three realms? Then one must consider what characteristics the Land of Bliss (sukhāvatī) has, and match them against each of the three realms one by one; only through comparison can one finally arrive at the correct conclusion. This line of thinking stays closely tied to the topic. Students who are good at writing essays in school know that essays must stay closely tied to the topic; especially during exams, if you go off topic, no matter how well you perform, you will fail and may even get a zero.  

If asked what the characteristics of the three realms are, you must consider the characteristics of the desire realm, the characteristics of the form realm, and the characteristics of the formless realm, and then consider what the characteristics of the Western Land are. Compare them with the characteristics of the three realms, and through comparison you will know whether the Western Land is within the three realms or outside them. That is the approach to this question—very simple. Of course, this is knowing by inference. Although the result may be correct, or even entirely correct, it is not known through direct observation, and does not count as knowing through personal realization. Direct observation allows one to know without comparing the two. Knowing by inference is knowing through the mind consciousness making comparisons. Direct knowing involves not only the mind consciousness making present observation within meditative concentration, but also the manas observing together with the mind consciousness, or independently engaging in deep deliberation (manasikāra), finally arriving at a conclusion that accords with the facts. Without meditative concentration, none of this can be achieved.  

What are the characteristics of the desire realm? First, the sentient beings in the desire realm have the dharmas of the five aggregates and eighteen realms, have material form such as the material world of mountains, rivers, and the great earth, and have mental dharmas of the eight consciousnesses. The consciousnesses have wholesome, unwholesome, and neutral (avyākṛta) mental factors; they have ignorance, greed, hatred, and delusion, with greed and desire being dominant, greedily attached to all dharmas within the desire realm. What are the characteristics of the form realm? The sentient beings in the form realm have the four dhyānas and eight absorptions, the most basic being the first dhyāna. They have material form—the physical body and the material world—and mental dharmas of eight consciousnesses, or seven, six, five, four, or three consciousnesses. Their mental factors include only wholesome and neutral ones, without unwholesome mental factors; the unwholesome mental factors are subdued and suppressed, not necessarily eradicated. The concentration mental factors are prominent; they are constantly in meditative absorption, and afflictions do not manifest.  

What are the characteristics of the formless realm? The formless realm, as the name implies, is without form: there is no material world of palaces, mountains, rivers, or the great earth, and no physical body. Only the three consciousnesses—the sixth, seventh, and eighth—abide in the four formless absorptions. Their mental factors are neither wholesome nor unwholesome; all afflictions have been subdued, though not necessarily eradicated, and the concentration mental factors are even more prominent and evident.  

What are the characteristics of the Western Land of Bliss? In the Land of Bliss's land where ordinary beings and sages dwell together, there are bodhisattvas of all stages above and including avaivartika (non-retrogression), as well as ordinary sentient beings below avaivartika who have not seen the mind and have not realized any fruit. These sentient beings all have the five aggregates and eighteen realms; they have material form—physical bodies, palaces, flowers, grass, trees, the great earth, rivers, ponds, and so on—and mental dharmas of the eight consciousnesses, with mental factors that are wholesome and neutral to varying degrees, and no unwholesome mental factors. As for the bodhisattvas' meditative concentration—even the ordinary sentient beings, because they have long dwelt within lotus palaces, have had their mind consciousnesses transformed; they are no longer unwholesome, no longer scattered and distracted, all possess meditative concentration, and their minds abide in concentration, single-mindedly contemplating the Buddha's Dharma. The bodhisattvas' greed and desire have of course all been subdued or eradicated; the ordinary sentient beings' greed and desire, though not eradicated, have been subdued.  

Since this is so, the Land of Bliss has the characteristics of the form realm and also the characteristics of the desire-realm heavens, but not the characteristics of the formless realm. Therefore the Land of Bliss belongs to the dharmas within the three realms and is not outside the three realms. Only arhats after Nirvāṇa without remainder are outside the three realms and not within them; even the Buddhas and bodhisattvas are not outside the three realms, and moreover they vow that as long as sentient beings are not all delivered, they will never leave the three realms and will not enter nirvāṇa. Because outside the three realms there are no worldly dharmas at all: no material form, no mental dharmas of the seven consciousnesses; the dharmas of the five aggregates and eighteen realms have all ceased, and only the eighth consciousness does not cease. How could the Buddhas and bodhisattvas extinguish their own five aggregates and eighteen realms and deliver sentient beings without a body of the five aggregates? Therefore the Land of Bliss and all Buddha-lands are within the three realms, and the Buddhas and bodhisattvas are also within the three realms, forever together with sentient beings of the five aggregates.