The fundamental question regarding the Lotus Sutra’s vision of ultimate truth is its relation to the essential teaching of the Prajn͂āpāramitā sutra, the doctrine of emptiness (śūnyāta). While the sutra does not expound the principle of emptiness at great length, it refers to emptiness on several occasions, and many of its principles and teachings appear to presuppose the concept of emptiness. One of the most extensive direct references to it appears in chapter 5:

Those grasses and trees, shrubs and forests, and medicinal herbs do not know themselves whether their nature is superior, intermediate or inferior; but the Thus Come One knows this Dharma of a single mark and a single flavor, namely, the mark of deliverance, the mark of disenchantment, the mark of extinction, the mark of ultimate nirvāṇa of eternally quiescent nirvāṇa, finally reducing itself to Emptiness. (p. 103)

In this passage the sutra declares that despite their apparent diversity, the ultimate truth of all beings is the single mark of emptiness. Later, in chapter 10, the sutra further expounds that it is through the realization of this emptiness of the dharmas that one gains entrance into Buddhahood:

The room of the Thus Come One is the thought of great compassion toward all living beings. The cloak of the Thus Come One is the thought of tender forbearance and the bearing of insult with equanimity. The throne of the Thus Come One is the emptiness of all dharmas. It is only by dwelling securely among these that he or she can with unabating thought broadly preach this Scripture of the Dharma Blossom to the bodhisattvas and the fourfold assembly. (p. 180)

In addition to statements such as these directly referring to emptiness, passages which proclaim a singular ultimate truth of all dharmas or which deny any distinction between the phenomenal realm and ultimate truth may be viewed as expressions of this doctrine. Thus, a passage in chapter 2 which states that the “reality” of all aspects of all dharmas is their “suchness” (tathatā) appears to be a reference to the emptiness of the dharmas:

Concerning the prime, rare and hard-to-understand dharmas, which the Buddha has perfected, only a Buddha and a Buddha can exhaust their reality, namely, the suchness of the dharmas, the suchness of their marks, the suchness of their nature, the suchness of their substance, the suchness of their powers, the suchness of their functions, the suchness of their causes, the suchness of their conditions, the suchness of their effects, the suchness of their retributions, and the absolute identity of their beginning and end. (pp. 22-23)

In chapter 16 the Lotus Sutra asserts the identity of the world of samsara, the cycle of birth and death, and the realm of the Buddha, a central theme of the exposition of emptiness in the Prajn͂āpāramitā sutras. Using vivid language the Lotus Sutra explains that the transient phenomenal world, which to the unenlightened is a place of torment, is itself the “pure land” of the Buddha:

When the beings see the kalpa ending
And being consumed by a great fire,
This land of mine is perfectly safe,
Ever full of gods and men;
In it are gardens and groves, halls and towers,
Variously adorned with gems,
As well as jeweled trees with many blossoms and fruits, Wherein the beings play and amuse themselves;

My Pure Land is not destroyed,
Yet the multitude, seeing it consumed with flame,
Are worried, and fear the torment of pain;
The likes of these are everywhere. (p. 243)

Another motif of the Lotus Sutra that associates it with the tradition’s expositions of emptiness is the distinction made between the revelation of the Buddha Dharma in this sutra and the “expedient devices” the Buddha has previously used to lead practitioners to this truth. The Lotus Sutra is famous (or infamous) for denouncing the doctrines taught to the Śrāvakas (voice-hearers) as “expedient devices” intended only to prepare the practitioner to grasp the truth revealed in the sutra. In one passage, the “nirvāṇa” taught to the voice-hearers is repudiated explicitly on the grounds of the emptiness of all dharmas:

Though I preach nirvāṇa, This is no true extinction.
The dharmas from their very origin
Are themselves eternally characterized by the marks of quiet extinction. (p. 37)