The Three Vehicles are:
Bodhisatta / Bodhisattva: The Bodhisatta is one who Enters the Dharma Stream by them self; without hearing the Dharma preached; and makes a vow to save all living beings. The completion of this path {Arahant / Arhat} is Sammasambodhi {Samyaksambodhi}; which takes many lifetimes. A Sammasambuddha appears at a time when all Traces of the prior Sammasambuddha are completely lost; and starts a new Dharma Dispensation.
Pacceka-Pratyeka: This is also one who Enters the Dharma Stream without hearing the Dharma preached; but only seeks personal salvation, and never preaches Dharma. The completion of this path {Arahant / Arhat} is Paccekabodhi {pratyekabodhi}. Pratyeka has several etymologies. One of these is ’caused awakened.’ Another is ’self-enlightened’ or ‘private.’
Savaka / Shravaka: Those who enter the Dharma-Stream only after hearing the Dharma that has been preached by a Sammasambuddha {Samyaksambuddha}. The Shravakas preach the Dharma taught by the Sammasambuddha who taught them. Shravaka means ‘one who hears the voice [of the Buddha].’
In Theravada Buddhism, these vehicles are mutually exclusive. However, they all lead to Unbinding {Nibbana / Nirvana}, also called Purification {vishuddha}. So, from that viewpoint, Nirvana is the One Vehicle; the one thing they all have in common.
Over time, the concept of Buddhahood came to be conflated with Sammsambodhi. In Mahayana, the Nirvana of the Pratyekabuddha and Anubuddha came to be viewed as partial, lesser attainments. The path of Bodhisattva came to be seen as sort of the One Vehicle. This required changing the definition. It all gets a bit murky. Some thought the Pratyeka and Shravaka could never attain real Buddhahood. Others thought they could renounce Nirvana, become Bodhisattvas, and eventually become Samyaksambuddhas.
The Lotus Sutra resolves all this {implicitly} with the concept of Mutual Exclusion. So the Bodhisattva, Pratyeka, and Shravaka are no longer separate vehicles; but aspects of one compete praxis. All attain the One Buddha Vehicle of Complete and Correct Buddhahood {Samyaksambodhi}.
The concept of a Unique Samyakambuddha is retained in Mahayana, but only as a provisional or relative truth. That unique Provisional Buddha, for us is the historical Buddha, Gotama aka Shakyamuni. In some far distant future, his Provisional Dharma will be lost. Then, a new Buddha, Metteya or Maitreya; shall appear to restore a Provisional Dharma.
Of course, the Reality Dharma never really appears, nor does it ever disappear. It is only the Trace Provisional Teachings that get lost, and need to be restored. The Trace is derived from the Source. So, the One Vehicle is the Source-Gate Dharma that is always present in the World, never aging nor dying, never rising nor falling. It is Un-born, Non-arisen, Uncreated, and Unconditioned.
The Samyaksambodhi or Complete and Correct Buddhahood of the One Vehicle is awakening to our inherent Buddha Nature; which has the 4 qualities of Pure Beauty, Stable Bliss, Constant Immediacy, and Selfless Self. We already possess these qualities; but they are asleep. We need to wake them up, summon them from the underground, so to speak, by chanting Daimoku.
This differs from the three kinds of Acquired Awakening: Sammasmbodhi, Pratyekabodhi, and Anubodhi. Those are relative and provisional; and are acquired by creating or earning relative merits. Relative merits are qualities like Empathy, Patience, Intelligence, and Compassion. Those are, of course, still good things to work on. As our Buddha Nature starts to be emerge, it is natural to want to be a good, kind person and earn merit.
I apologize for any typos; which I shall see right after I click Post. Also, this is all, of course, only my view. Others should seek their own understanding. I think my view is correct, otherwise it would not be my view. However, I might be wrong, so I am non-attached to views. I reserve the right to change my mind; and yield back the remainder of my timelessness.

The three vehicles are Ford, GM, and Chrysler. The One Vehicle is Honda [Kempon Hokke]. It used to be Toyota[Soka Gakkai]. The significance is that if you want a trouble free car that will last for years with good acceleration and handling, you will choose a Honda [Kempon Hokke].

Let’s say for the sake of argument that you absolutely do not believe in rebirth/reincarnation/metaphysical afterlife processes and so on. In that case, are the Three Vehicles still meaningful at all? I think they are. Let’s take a look.
The Arhat in classical Buddhism is someone who has broken the fetters of belief in a substantial self, superstitious reliance on rites and rituals, skepticism in regard to the Three Jewels (Buddha, Dharma, Sangha), sensual craving, hatred, clinging to form real existence, clinging to formless realm existence, restlessness, pride, and the fundamental ignorance (re suffering, its causes, its cessation, and the Path). By breaking through these fetters the arhat will no longer be reborn anywhere in the six worlds of rebirth (including the heavens of desire, form, and formlessness).
So if there is no rebirth, what is the point of trying to be an arhat - since there is no such thing as reincarnation anyway?
I would say, however, that despite our scientific materialistic worldview we still go through the six worlds as psychological or subjective realities. Furthermore, we still approach the future with both fear (that something bad will happen to us and/or that we’ll get what’s coming to us) and longing (that we’ll achieve or hopes and/or that we’ll get what’s coming to us). Even though as modern or post-modern people who know for a scientific fact that when we die the epiphenomena of consciusness will fade away as our brain’s cool we still look approach the moment of death with fear and/or longing. The arhat faces death having uprooted all fear and longing. They are totally cool with it. (The word nirvana means “to extinguish” as in extinguishing the blazing fire of the three poisons, so in effect an arhat who realizes nirvana is “totally cool.”) It doesn’t matter if there is or is not rebirth as a literal fact. The arhat is cool in every moment, even the moment of death.
Same for the pratyekabuddha, except they realized this on their own without the help of the Dharma and/or they spent a lot of time on their own deepening their understanding and appreciation of the selfess nature of causality.
The Bodhisattva is one who has broken the fetters and yet realizes that there is a level of ignorance beyond just realizing the no-self nature of themselves and others. They realize the emptiness of all phenomena and realize that there is a more fundamental ignorance to break through - the jneya-avara or hindrance of dualism. They further aspire out of compassion to remain engaged in samsara (the process of rebirth) so they can also become Buddhas and liberate other beings. But of course if rebirth is a scientific impossibility, this does not make any sense. When you die you die and there’s no coming back - no matter how much you want to be reborn in every realm of suffering for the sake of all beings.
I would say, however, that the Bodhisattva attitude is in fact deeper and more existentially meaningful than the coolness of the arhat. The Bodhisattva is not simply content with simple acceptance of what is. They have a more positive attitude. They face each moment, including the moment of death, as a moment in which they can be positively engaged for the sake of all beings. And if it should turn out that science is wrong and we do have to be reborn, they are fine with that. In fact they are happy that they can stay engaged. They are still cool with whatever arises (or ceases) but there is a deeper fearlesness in that they are not afraid to be involved and even purposely stay compassionately engaged.
As for Buddhas, they are bodhisattvas par excellence who realize that the ultimate reality has nothing substantial to lose and nothing substantial to gain. They remain creatively engaged without any sticking or fretting. It is a supreme gracefullness that doesn’t worry a bit if there is rebirth or not, because it no longer thinks in terms of selves who can be reborn or not, or who can be engaged or not. This supreme unselfconscious realization is where all the other paths are aiming at. There is no question here of how can I escape suffering, or how can I help, or what’s in it for me, but just a selfless apprecation and a playful but earnest liberated/ing presence.
Anyway, that’s how I think of it at this time.
Namu Myoho Renge Kyo,
Ryuei

Dear Patrick:
How much more difficult is it to practice as the Lotus Sutra teaches?
Mark

Mark asks, “How much more difficult is it to practice as the Lotus Sutra teaches?”
It is simple. Respect for others, even those that appear to act disrespectfully towards others in thought, word, or action.
The Bodhisattva Never Disparaging Chapter is the chapter Nichiren refers to, in his own practice of the Lotus Sutra.
Patrick

>>> Voice hearers, Arhats, etc, those below the level of total and complete enlightenment, such as Shakyamuni’s disciples.
The awakening of the Arhat is the same as the awakening of the Buddha. The Samyaksambuddha is also an Arhat. Anubuddhas and Prayekabuddhas are also arhats. You are just getting hung up on the words anutarra samyaksambodhi. It is only a provisional concept.
By definition, anyone who receives instruction in the Dharma is a Savaka — one who hears [the Buddha's] voice. So we are voice hearers. We all must awaken to teacher-less knowing {anacharya jnana} by ourselves, so we are all cause awakened paccekas. All who share their merits and tell others about Dharma are doing the Bodhisattas, so we are all destined to be Sammasambuddhas. That is the general meaning. The Three Vehicles also have specific meanings.

Dear Robin,
You see my expression or opinions as griping; a negative view. I come here voluntarily. You blog here to make a point. You missed an opportunity to get something positive called feedback, because you see feedback; i.e. other opinions that are not yours as negative. You then question my Buddhist practice and it’s correctness based on your actions and observations from the internet.
If I point out an obvious outcome, and it angers you, self reflection might be the path to take instead of shooting the messenger.
I know the answer and gave it regarding The Three Vehicles and The One Vehicle, easily just as the eight year old Dragon Girl did. You just failed to see it so I will tell you another way.
All those whom believe enlightenment is not inherent in their own life and can not readily show actual proof of their own faith, are practicing the Three Vehicles.
Those whom are aware of their enlightenment and practice with that realization are practicing the One Vehicle.
It’s about what ‘you’ believe and not what “I” believe of your practice.
The One Vehicle is the Vehicle of self realization of the Wonderful Law inherent in ALL life EQUALLY.
Nam Myoho Renge Kyo, Like the Roar of the Lion!
Patrick

Actual proof means the person is convinced by what happened, that they could interpret it as actual proof. It’s completely subjective. In order to have real actual proof I would need at least two of myself, one to follow the teachings, and one not to then I could see the difference in following the teachings or not. If I didn’t like the outcome I could say the sample was too small to be scientific so maybe I need a thousand of me, five hundred who follow and five hundred who don’t. Then I could say I have actual proof in a real sense. As commonly used though actual proof means I think I achieved something through my practice but it proves nothing to anyone but me.

Patrick,
You have no idea what I am thinking. I simply observe that nearly everything you post is a complaint. I completely disagree wit your take on most things; but that is nothing personal. That does not make you wrong or stupid. I am capable of collegial disagreements. You seem to be unable to cheerfully disagree.
I blog here because I enjoy discussing Karma. I give my honest take on things. I do not claim to know all the answers. I am quite comfortable with a level of agnostic ambiguity. I think it is more likely you that post here to promote an agenda. Maybe you are projecting?
I think one thing that annoys me is when people display a strong emotional attachment to views. It is like if they are wrong; it would a shattering experience. Anyway, if something annoys me. that is my problem.

“I can read instructions on how to enter a meditative absorption. I can also read a description of what it is like. The actual proof is what I experience when I put it into practice. If I am doing it right; then that experience should fit the description…”
Is it then possible that by following something with an expectation of a defined result changes the experience, by virtue of the fact that you are observing the results?
thank you
Bill

Bill,
I suppose so. In the case I described; I doubt it. For example, there are 5 elements of the 1st level of absorption: directed thought, rapt attention, emotional joy, bliss, and ekagatta. I do not see how knowing that shapes the experience. I can not talk myself into emotional joy. It just happens or not. The results are repeatable. Tests show that the practice improves measurable cognitive skills.
The other thing is that I experienced some things practicing object meditation prior to reading the descriptions.
Also, at times; I might experience melancholy, doubt, enmity, agitation, and sense desires. That means my effort failed.

> All those whom believe enlightenment is not inherent in their own life and can not readily show actual proof of their own faith, are practicing the Three Vehicles.
That is just total nonsense. Nothing personal at all. It is just incorrect.
> The Lotus Sutra describes the Three Vehicles as unnecessary and incomplete. te world of Voice hearers, Arhats, etc, those below the level of total and complete enlightenment, such as Shakyamuni’s disciples.
I think that is close to what provisional Mahayana teaches. I think provisional Mahayana teaches that the path of shravaka and pratyeka lead to an incomplete awakening. That only Bodhisattva leads to complete and perfect awakening. I think the Lotus Sutra overturns that. It basically says that all three vehicles lead to the One Vehicle of Buddhahood. I also fail to see how that is essentially different from what Theravada teaches.
BTW, in the Suttas, Arhat {called arahant} is the final stage of all three vehicles. The anubuddha, paccekabuddha, and sammsambuddha are all arhats. The Buddha predicted Devadatta would become an arahant {arhat} via the pacceka {pratyeka} vehicle. That suited him; because he did not play well others.
Now, I think one way the Lotus Sutra differs is with mutual inclusion; which I think is already implicit in Theravada anyway. Another difference is that Mahayana goes into more detail describing the nature of Nirvana. The Nikayas talk about unbinding, liberation, and purification. Also about seeing things as they really are, However, the ultimate is described in negative terms. It is, for example, a liberation from attachment to ugliness, stress, inconstancy, and the ego.
The Buddha said there is an un-born, a non-arisen, an uncreated, and an unconditioned; but those are only adjectives. He leaves it for the disciples to see it for themselves. Mahayana maybe gives us more hints. It offers conceptual descriptions and creates visual imagery.
The Buddha said that there is a cessation {the term for cessation literally means an escape from confinement} of dukkha. Some schools of thought — in both Theravada and Mahayana — take that as a cessation of everything, an Emptiness or dissolution. However, it could also be a renaissance of something better. The Buddha said that all sankhara or conditioning is dukkha; he did not say all dhammas or phenomena are dukkha. There are also unconditioned phenomena; the attributes of Nirvana; which are not dukkha.

I am not attached to my views. It appears the bloggers are attached to theirs here.
Guest Blog, define guest, a visitor, not an inhabitant.
You can call me a whiner, name-calling perhaps may fit you well. It is easier to call out someone you disagree with, than it is to reflect on the issue itself.
Remove your Guest Blog and call it an aditional Blog for your regular bloggers.
Just an observation.
of course this group lacks the ability to hear any opinions other than their own. Attached to your own opinions, while you accuse others of the sameact.
It is called finger-pointing. A human trait
Patrick

When we update this site, the Guest Blog will go away. We thought readers would want to write once in awhile, but that didn’t happen. The update will have a main page blog to keep readers up to date and to put these “Question of the Week” posts.
I have found this very interesting, though I have not read every word. Thanks to everyone for their input.