user16903: I read that the guidance of a teacher is "highly recommended because not all meditation experiences are spiritually skillful" and that

"It's also very common for solo practitioners to believe they have reached a deep meditative state when in fact they have barely scratched the surface. They may feel the rapture of the first dhyana, for example, and assume that's enlightenment. A good teacher will guide your meditative technique and keep you from sticking anywhere."
Developing Samadhi

Can we take a deep and authentic look, and potentially reach enlightenment without a teacher?
thanks

user295: You need another's voice (parato ghosa) or spiritual friend to teach you dhamma. Other than for a Buddha and Private Buddha one cannot realise the Dhamma without someone else showing the path. So you need someone to show you how to get too deep meditation. Also, show you where you might have made mistakes.
Once you learn the path it is one's efforts and practice which takes you to the final goal. You should be an island to your self without relying on another.
So to learn the technique you need the guidance of a teacher. To walk the path you need to do it your self. No external party can help here. Generally, you lean a little bit of theory and put it to practice then learn more and put that into practice. Hence it is good to have a teacher who can show you the way.
The medium thought what is taught can be direct interaction with a teacher. Reading books. Or even directly from the Tripitaka. The ultimate teacher in the line of teachers is the Buddha who made the Dhamma know.

user7628: Anything that can be learned how to be done most likely could be learned more quickly with a teacher. This applies to deep meditative states. That being said, It does not apply to enlightenment.
Nothing is required to reach enlightenment. Nirvana exists with us in every moment of our lives. Because of this, all you need to do to "reach" enlightenment is to see it clearly. Reaching deep meditative states are not required to awaken. Spontaneous enlightenment is possible and has most likely happened many times before. Awakening is not something that is done. It is more like the opposite. It is a stopping of doing. And once you stop that doing, all that is left is Nirvana.
A teacher can be helpful only in pointing you in the direction of where to look, how to look, and how to stop looking. From personal experience though, I have seen no evidence that anything can expedite the process of awakening. Awakening is only a gradual process in very select circumstances. Most awakenings are happen in a single moment and are instantly life changing. My awakening happened over two meditation sessions. The first was a sort of half baked awakening, but then 2 days later the real thing happened and blew everything open. I would say I am probably the exception as opposed to the rule though.
TLDR; Teachers are not required to help you reach meditative states, but they can be very helpful. Teachers are not required to help you reach enlightenment, but they can point you in the right direction.

user8157: A teacher is generally required but difficult to find. The Pali suttas say:

Tathāgatappaveditassa dhammavinayassa desetā puggalo dullabho lokasmiṃ
Rare in the word is a person who teaches the teaching and training
  proclaimed by a Realized One.
AN 6.96

For an individual with a keen intellect, this 'teacher' could simply be the Pali suttas. However, even in this case, the discernment of what the Path is must be acutely discerned. Generally, even an intelligent person needs a 'rare teacher' to verbally guide through the true meaning of the Pali suttas. 

16903: <p>I read that the guidance of a teacher is &quot;highly recommended because not all meditation experiences are spiritually skillful&quot; and that</p>
<blockquote>
<p>&quot;It's also very common for solo practitioners to believe they have reached a deep meditative state when in fact they have barely scratched the surface. They may feel the rapture of the first dhyana, for example, and assume that's enlightenment. A good teacher will guide your meditative technique and keep you from sticking anywhere.&quot;</p>
<p><a href="https://www.learnreligions.com/samadhi-449923" rel="nofollow noreferrer">Developing Samadhi</a></p>
</blockquote>
<p>Can we take a deep and authentic look, and potentially reach enlightenment without a teacher?</p>
<p>thanks</p>
 295: <p>You need another's voice (parato ghosa) or spiritual friend to teach you dhamma. Other than for a Buddha and Private Buddha one cannot realise the Dhamma without someone else showing the path. So you need someone to show you how to get too deep meditation. Also, show you where you might have made mistakes.</p>

<p>Once you learn the path it is one's efforts and practice which takes you to the final goal. You should be an island to your self without relying on another.</p>

<p>So to learn the technique you need the guidance of a teacher. To walk the path you need to do it your self. No external party can help here. Generally, you lean a little bit of theory and put it to practice then learn more and put that into practice. Hence it is good to have a teacher who can show you the way.</p>

<p>The medium thought what is taught can be direct interaction with a teacher. Reading books. Or even directly from the Tripitaka. The ultimate teacher in the line of teachers is the Buddha who made the Dhamma know.</p>
 7628: <p>Anything that can be learned how to be done most likely could be learned more quickly with a teacher. This applies to deep meditative states. That being said, It does not apply to enlightenment.</p>

<p>Nothing is required to reach enlightenment. Nirvana exists with us in every moment of our lives. Because of this, all you need to do to "reach" enlightenment is to see it clearly. Reaching deep meditative states are not required to awaken. Spontaneous enlightenment is possible and has most likely happened many times before. Awakening is not something that is done. It is more like the opposite. It is a stopping of doing. And once you stop that doing, all that is left is Nirvana.</p>

<p>A teacher can be helpful only in pointing you in the direction of where to look, how to look, and how to stop looking. From personal experience though, I have seen no evidence that anything can expedite the process of awakening. Awakening is only a gradual process in very select circumstances. Most awakenings are happen in a single moment and are instantly life changing. My awakening happened over two meditation sessions. The first was a sort of half baked awakening, but then 2 days later the real thing happened and blew everything open. I would say I am probably the exception as opposed to the rule though.</p>

<p>TLDR; Teachers are not required to help you reach meditative states, but they can be very helpful. Teachers are not required to help you reach enlightenment, but they can point you in the right direction.</p>
 8157: <p>A teacher is generally required but difficult to find. The Pali suttas say:</p>

<blockquote>
  <p>Tathāgatappaveditassa dhammavinayassa desetā puggalo dullabho lokasmiṃ</p>
  
  <p>Rare in the word is a person who teaches the teaching and training
  proclaimed by a Realized One.</p>
  
  <p>AN 6.96</p>
</blockquote>

<p>For an individual with a keen intellect, this 'teacher' could simply be the Pali suttas. However, even in this case, the discernment of what the Path is must be acutely discerned. Generally, even an intelligent person needs a 'rare teacher' to verbally guide through the true meaning of the Pali suttas. </p>
