So, I'm going to take a stab at an explanation of what the Buddha means by Expedient Means in the Lotus Sutra.
My analysis is influenced by Zhiyi and his lineage (Tientai/Tendai/Nichiren). I don't know everyone's backgrounds, so excuse me if this is too obvious. Zhiyi is the
authority on the Lotus Sutra in East Asian Buddhism. I don't think its too much to say that he is the most influential Buddhist scholar in East Asia. Almost everyone since him has been operating within or in tension with the paradigm he established. In Zhiyi's view, the Lotus Sutra and to a lesser extent, the Mahaparinirvana Sutra, express the Buddha's most profound teaching. The idea of Expedient Means figures prominently in his ideas. I'm going to sort of try to channel Zhiyi here.
Here is a key passage from the Lotus Sutra
where the Buddha sums up his true intentions and his own practice:
You wise ones, do not give in to doubt!
Banish all doubt forever!
The Buddha’s words are true, never false.
It is like the physician
Who proclaimed his own death,
Although it was untrue.
He did this to cure his delirious sons,
Through excellent skillful means;
So no one could say he really spoke falsehood.
I, also, being the father of the world,
Cure those who suffer.
To the deluded and unenlightened I say that
I have entered nirvana,
Although, in fact, I am really here.
For if they were to see me,
They would become lazy and arrogant.
Attached to the desires of the ﬁve senses,
They would fall into the troubled states of being.
Always aware of which sentient beings
Practice the path and which do not,
I teach the Dharma in various ways,
According to their ability to be saved.
I am always thinking:
By what means can I cause sentient beings to be able to
Enter the highest path
And quickly attain the Dharma?
How do we reconcile those two lines I emphasized above?
I'm going get to an answer, in a round about way, by using some comments above characterizing the Buddha as being deceptive, or resorting to deceptions, as a pivot. In doing so, I'm going to criticize those comments, but I don't mean it personally. I, being a person who has taken faith in the Buddha, cannot characterize the Buddha as being deceptive, and I am compelled to take issue with these kinds of comments about him. Now, that is a formalistic attitude. In a more practical sense, I'd urge my fellow Dharma brothers and sisters to take care in using words that could disparage the Buddha or bring him into disrepute. We don't know who is reading our comments, and our 'shop talk' could be misconstrued by others who become discouraged and turn away from the Dharma.
OK first, some background. Zhiyi had several systems for classifying the Buddha's teachings. The most prominent are the four divisions according to teaching, four divisions according to method, and five divisions according to sequence. The Four Teachings is relevant here.
In a few words, the Four Teachings categorize teachings of the Buddha based on how the Provisional and Absolute Truths are related to each other.
The Four Teachings are:
2. Provisional Mahayana
These two approaches are similar in that they are dismissive of the Provisional Truth in favor of the Absolute. In the case of the Hinayana, its about Anatman; in the case of Provisional Mahayana, its about Sunyata. Both of these approaches are criticized by Zhiyi for bias in favor of the Absolute Truth.
Zhiyi relied on a three truth innovation to expound his thought, in contrast to Nagarjuna's Two Truth convention.
3. Separate Teaching - There are two basic approaches here within the Separate Teaching, both involving a Three Truth Structures - Provisional, Absolute and Middle. In one approach, you have the dependently originated provisional truth in contrast to the absolute truth of emptiness being like two sides of a coin - you can only have one at a time. The Middle Truth is a fluency moving back and forth between these two Truths, utilized by the Bodhisattvas who themselves dwell in the Absolute, but resort to the Provisional to carry out their work of saving beings. A second approach has the Provisional/Absolute structure subsumed within an all encompassing Middle Truth - the "Emptiness of Emptiness". In this case, the bodhisattva constantly dwells in the "emptiness of emptiness", resorting to expedients that are in instances not just provisional, but in some instances are absolute.
4. Perfect Teaching - This is a three truth structure in which the Provisional, Absolute and Middle are completely integrated such that they are not really three separate truths so much as three aspects of a single truth; starting with any of the three, one can deduce the other two. This is the basis of the Buddha's practice. For an explanation of this, see Swanson, Ng and Ziporyn - especially Ziporyn - I don't have the ability to do the subject justice.
The suggestion that the Buddha engages in deception sounds like it would be a Hinayana or Provisional Mahayana view, or at best, a Separate view. It presumes that there is a perspective that is True in contrast to the expedients. This view echos a common distinction we find, not only in Buddhism, but in many philosophical systems - the dichotomy between the provisional truth and the absolute truth, however those terms are conceptualized - the former as convention, as designation, as delusion, as conditioned, etc. and the latter which is the ultimately objective - the way things really are, Truth with a capital "T". To say that there is a deception, we express a bias in favor of the absolute and the thing we are calling a deception, in this case, the expedients to which the Buddha resorts in order to save living beings, is false in comparison. Zhiyi would call this a 'crude' statement. * EDIT - In Zhiyi's view of the Perfect Teaching, All Provisional Truths are Absolutely True, even as they are Absolute (devoid of Self).The Buddha’s words are true, never false.
How do we reconcile the doctor sending word of his death to his children with the Buddha's words being True?
We, ordinary beings, are mired in delusions. Despite constantly, as we are, living in the Buddha's Pure Land, we don't see it as such. What the Buddha sees as Bliss, we see as Hell, or whatever place our delusion conditions. Despite our delusions, however, from the perspective of the Buddha, we are always dwelling in the true aspect, the absolute reality, constantly progressing on the path of awakening, whether we know it or not. Think of the light emitted from the Buddha's head illuminating the lands of the East described in the first chapter. That is what the Buddha sees. He sees being making good, bad and neutral causes; he sees their capacity, receptivity, their accomplishments and failures on the path to awakening. He sees them attaining awakening and passing into Parinirvana. That is the True Aspect, the Buddha's own view, and completely includes all of our delusions within his purview. Its not the tertiary Middle of the second of the two Separate Teaching structures I described above, because all of reality is integrated completely, as it is, into the Buddha's world. That is why the Buddha is able to respond to the needs of beings. If he was separate in his enlightenment, if the delusion was not relatable to his awakening, there would be no possibility of the Buddha interacting with us.
The Buddha, who is constantly in this world, sometimes appearing as a Buddha, at other times appearing as someone else, is always administering therapeutic advice to draw us along the path in the reality of his world. Mired in delusion, the things we think are real, are not. How can we presume that anything the Buddha says to us is not true, when our standard itself lacks any substantial reality? Its like asserting that a turtle fur coat is not real because of the antlers of a rabbit. Even realization of Emptiness however its conceived, even in the non-conceivable Emptiness of Emptiness iteration, in the Perfect Teaching, is marked by nescience, however subtle.
When the Buddha tells the children absorbed in their play, that there are toys outside, he successfully gets the children out of the house - that was the only reality - the children's obsession with toys is their delusion and their pursuit of them was more delusion. Even the gift of ox carts is just more satisfaction of their vanities. The Children's expectations and their actions based on those expectations were delusion upon delusion, as are the rewards of their actions. When the children drink their father's medicine out of desperation on the news of their father's death, that's the only reality - they took the medicine and were cure of the effects of poison.
When I am absorbed by loathing of my fellow, I am unable to progress in my practice. As the Buddha recommended, I contemplate how this fellow, at some point during our churning in samsara, was my mother who gave selflessly to me. The contemplation has the effect of ameliorating my loathing and replacing it with the positive disposition of loving-kindness. The substance of my contemplation is pure fiction - I have no actual recollection of this relationship. It is a therapeutic illusion to counter loathing I felt because of another illusion - that this person wronged me and should be the object of ire. Yet, the amelioration of loathing is real. The obstacle of hatred is removed and I am able to progress on the path, the only reality. As I progress toward awakening, the Buddha will prescribe cures for the further defects I uncover, and on, endlessly, until in the place of practice, the goal will be achieved.
The only reality is the path and the goal. There is no deception on the Buddha's part. Only expedient means.