user-1: An answer has prodded me to completely reconsider my understanding of Buddhism and emptiness [this answer]. I never realized that Buddhism involves the dismantling of preconceptions and false certainty. Due to some spiritual experiences, I feel it's clear that the path to a happier life for me is changing this. 
However, I know for a fact that I continuously generate such preconceptions and approximations almost pathologically. I feel that doubt greatly arises from this, in my mind; I keep making inexact and hasty conclusions, and assuming things. I cannot merely not know. 
My question is: What are the ways to dismantle such biases of mind? I specifically mean those of speculation, stereotyping, jumping to conclusions, and so on.
Simply put, I'm wondering how one trains or comes to accept uncertainty.

user-1: The habit of mind to Speculate and Stereotype is developed over thousand of years of psychological evolution. It was at some point in history, very important for humans to classify the objects, they saw and and hence speculation and stereotyping gave advantage, when the world around humans was not very complex. 
The point I am making is, these are habit patterns of mind created over thousands of past lives. 
As against 'jumping to conclusions', as we mean it in a judgemental sense, is some kind of recent phenomena of fast paced life. 
May be, even the stone age humans must have been jumping to conclusions at sight of some thing akin to snake.
So, I am trying to say, these are habit patterns of everybodies mind.
Now answering your question, how one trains to accept the uncertainity
The point of Buddhism is not to train the mind (there are therepies in modern psychology to do just that), instead we try our best to see things as they are. So the way to dismantle the bias is, to be aware to the present moment and be watchful of your mind as much as possible.
This gives rise to intelligence, and through that intelligence you dismantle the habit pattern.
When you fail, don't be judgemental towards yourself and feel bad. Instead make a note and understand that as all your intelligence was available what you did was the best you can do.
Through such repeated feedback your biases will be dismantled without specifically trying to train the mind which is a superficial and phony solution.
To put it simply, Stay Aware to the Present Moment.

user-1: I don't have any better advice than this song:
Mahamudra transcends all words
And symbols, but for you, Naropa,
Earnest and loyal,
I have to say this:

The Emptiness doesn’t need support,
Mahamudra rests on nothing.
Without making any effort,
One can break the yoke
Thus - reaching Liberation.

If one sees nothing when staring into space,
If with the mind one then observes the mind,
One destroys distinctions and reaches Buddhahood.

The clouds that wander through the sky
Have no roots, no home; nor do the distinctive
Thoughts, which float through the mind.
Once the nature of mind is seen,
Discrimination stops.

In space shapes and colours form,
But neither by black nor white is space tinged.
From the nature of mind all things emerge,
The mind is not tainted by virtues or vices.

The darkness of ages cannot hide the bright sun
Nor the long kalpas of samsara
can hide the splendid light mind.
Though words are spoken to explain the Emptiness,
Emptiness for itself can never be expressed.

This world is transient,
like ghosts and dreams, without any substance.-Tilopa

You can find it full here

user43: You are asking how to train in overcoming mind's tendency to stereotype and to reify superficial perceptions. Generally speaking, entire Buddhist path is about training in this. Much of the philosophical study (Madhyamaka) and practice of Zen and Vajrayana's higher tantras (Mahamudra and Dzogchen) are aimed at transcending the limits of superficial mind.
Working with a live contemporary teacher adds a practical aspect that is not readily explained in texts. This aspect has to do with application of Buddhist insights to everyday life. The superficial mind with its tendency for stereotyping keeps creating reoccurring patterns in one's personal life. It is by exploring and challenging these patterns that we get to see our superficial mind objectively. This leads to gradual disidentification and eventual freedom from stereotypical thinking.
In my personal experience undergoing this training, there are two parts to it. The first one is explained conceptually, for the student to practice on his own, between the periods s\he meets with the teacher. The second part is traditionally taught by the teacher in-person, without much explanation.
The part that's explained conceptually is a standard instruction on non-attachment. In my "lineage" it goes something like this: 

REMEMBER: every time whenever you feel a negative emotion in response to a real life situation,
assume the emotion comes from an "attachment" (a traditional word for preconceptions and stereotypes), then 
engage in 5-second introspection to quickly identify the specific attachment, then 
make a silent symbolic gesture of admonishing your ego for trying to protect its solidity, and then 
mercilessly take the attachment away from your ego,
FINALLY, watch the emotion subside and deal with the situation properly.

The act of giving up your attachment is designed to leave you highly vulnerable - but also much more open to other perspectives and frames of reference. By definition, the more a certain idea is important to you, the harder it is to let go of attachment. Ego is a master of rationalization and to be honest some of its reasons are actually pretty logical and often valid, but in context of this practice all these rationalizations must be ignored, and all attachments must be let go. The exercise gets seriously difficult when it involves dealing with other people over different interests and perspectives, especially when this is a real life or work situation, especially when you are right - but this is exactly what makes this practice so effective. 
The second exercise consists of your teacher occasionally pushing you to operate outside of your comfort zone. The normal student's reaction is to indulge in one's egoistic defenses until one day the student learns to get over them and open up to non-preconceptualized activity. This involves enormous creativity on the teacher's part, setting up all kinds of embarrassing situations in which the student is put on the spot and does not know how to react. It's hard to give specific examples since they tend to be very personal. A good Zen master or Vajra master has a talent for endless improvisation of these. The practice is both very painful and very effective for driving the student outside his or her preconceptualization.
In the absence of live teacher my advice is to get creative yourself and start finding ways to put yourself in situations when you do not have a good plan of action. Luckily, modern social life gives endless opportunities for trying one's luck outside one's comfort zone and watching oneself stumble.
Both of these exercises work by forcing the student to lay aside one's  preconceived notions, and practice operating in the preconceptual space of "beginner's mind".
It's seems awkward to explain all this in writing, as it is usually presented in a much more pithy and casual style in the middle of real life situations. Despite my limited ability to explain it with clarity, I can't overemphasize the importance of this practice. In my experience, it makes night-and-day difference in one's ability to comprehend and realize true Dharma. Hope it helps.

user17133: I've bumped into various prosaic and spiritual messages that have cultivated in me a certainty that most certainties are unjustified.
Studying debate in high school they drilled how to detect and avoid logical fallacies into us. It's easier to detect in the writing of others than your own, I find. If you can reliably detect them in your own thinking, you will cultivate a mental awareness that can help avoid these things. I could be wrong, but I think there's important elements of mindfulness involved with this process. I've found fallacies are used the most frequently when it comes to truths people don't want to face. 
I'd not try to avoid speculation. I'd actually encourage it, especially when it comes to criticizing what's going on in your head. What information could you acquire, at least in principle, that would prove you wrong? Employ any criticisms you might offer to someone else to yourself. I suspect this facilitates taming Ego. The other side of the coin has similar effects. Have compassion for yourself as you have compassion for others. 
Meditate. Watch your thoughts very carefully. What topics arise frequently in what order? Do you notice any patterns? You're likely to find there are some things you want to be true that might not be. That I suspect is the source of a lot of jumping to conclusions. 
Do not seek perfection. Perfection is Ego lying to you. Don't get discouraged from meditating because your thoughts take a long time to settle. Don't think that you just can't do it. 
These suggestions are heavily science/logic influenced, very linear. There's some problems stuck in thinking that way. I find Thich Nhat Hanh has a lot of great advice deviating from that pattern while cultivating understanding, especially in Zen Keys. He is very good at clarifying what information is being ignored when we try to contain things in our head with concepts. 
Hope that helps!

-1: <p>An answer has prodded me to completely reconsider my understanding of Buddhism and emptiness<a href="https://buddhism.stackexchange.com/a/26250/7302"> [this answer]</a>. I never realized that Buddhism involves the dismantling of preconceptions and false certainty. Due to some spiritual experiences, I feel it's clear that the path to a happier life for me is changing this. </p>

<p>However, I know for a fact that I continuously generate such preconceptions and approximations almost pathologically. I feel that doubt greatly arises from this, in my mind; I keep making inexact and hasty conclusions, and assuming things. I cannot merely <em>not know.</em> </p>

<p>My question is: <strong>What are the ways to dismantle such biases of mind? I specifically mean those of speculation, stereotyping, jumping to conclusions, and so on.</strong></p>

<p>Simply put, I'm wondering how one trains or comes to accept uncertainty.</p>
 -1: <p>The habit of mind to Speculate and Stereotype is developed over thousand of years of psychological evolution. It was at some point in history, very important for humans to classify the objects, they saw and and hence speculation and stereotyping gave advantage, when the world around humans was not very complex. </p>

<p>The point I am making is, these are habit patterns of mind created over thousands of past lives. </p>

<p>As against 'jumping to conclusions', as we mean it in a judgemental sense, is some kind of recent phenomena of fast paced life. </p>

<p>May be, even the stone age humans must have been jumping to conclusions at sight of some thing akin to snake.</p>

<p>So, I am trying to say, these are habit patterns of everybodies mind.</p>

<p>Now answering your question, <em>how one trains to accept the uncertainity</em></p>

<p>The point of Buddhism is not to train the mind (there are therepies in modern psychology to do just that), instead we try our best to see things as they are. So the way to dismantle the bias is, to be aware to the present moment and be watchful of your mind as much as possible.</p>

<p>This gives rise to intelligence, and through that intelligence you dismantle the habit pattern.</p>

<p>When you fail, don't be judgemental towards yourself and feel bad. Instead make a note and understand that as all your intelligence was available what you did was the best you can do.</p>

<p>Through such repeated feedback your biases will be dismantled without specifically trying to <em>train the mind</em> which is a superficial and phony solution.</p>

<p>To put it simply, Stay Aware to the Present Moment.</p>
 -1: <p>I don't have any better advice than this song:</p>

<pre><code>Mahamudra transcends all words
And symbols, but for you, Naropa,
Earnest and loyal,
I have to say this:

The Emptiness doesn’t need support,
Mahamudra rests on nothing.
Without making any effort,
One can break the yoke
Thus - reaching Liberation.

If one sees nothing when staring into space,
If with the mind one then observes the mind,
One destroys distinctions and reaches Buddhahood.

The clouds that wander through the sky
Have no roots, no home; nor do the distinctive
Thoughts, which float through the mind.
Once the nature of mind is seen,
Discrimination stops.

In space shapes and colours form,
But neither by black nor white is space tinged.
From the nature of mind all things emerge,
The mind is not tainted by virtues or vices.

The darkness of ages cannot hide the bright sun
Nor the long kalpas of samsara
can hide the splendid light mind.
Though words are spoken to explain the Emptiness,
Emptiness for itself can never be expressed.

This world is transient,
like ghosts and dreams, without any substance.-Tilopa
</code></pre>

<p>You can find it full <a href="http://buddhism.redzambala.com/buddhism/sutras/tilopa-mahamudra-song.html" rel="nofollow noreferrer">here</a></p>
 43: <p>You are asking how to train in overcoming mind's tendency to stereotype and to reify superficial perceptions. Generally speaking, entire Buddhist path is about training in this. Much of the philosophical study (Madhyamaka) and practice of Zen and Vajrayana's higher tantras (Mahamudra and Dzogchen) are aimed at transcending the limits of superficial mind.</p>

<p>Working with a live contemporary teacher adds a practical aspect that is not readily explained in texts. This aspect has to do with application of Buddhist insights to everyday life. The superficial mind with its tendency for stereotyping keeps creating reoccurring patterns in one's personal life. It is by exploring and challenging these patterns that we get to see our superficial mind objectively. This leads to gradual disidentification and eventual freedom from stereotypical thinking.</p>

<p>In my personal experience undergoing this training, there are two parts to it. The first one is explained conceptually, for the student to practice on his own, between the periods s\he meets with the teacher. The second part is traditionally taught by the teacher in-person, without much explanation.</p>

<p>The part that's explained conceptually is a standard instruction on non-attachment. In my "lineage" it goes something like this: </p>

<ol>
<li>REMEMBER: every time whenever you feel a negative emotion in response to a real life situation,</li>
<li>assume the emotion comes from an "attachment" (a traditional word for preconceptions and stereotypes), then </li>
<li>engage in 5-second introspection to quickly identify the specific attachment, then </li>
<li>make a silent symbolic gesture of admonishing your ego for trying to protect its solidity, and then </li>
<li>mercilessly take the attachment away from your ego,</li>
<li>FINALLY, watch the emotion subside and deal with the situation properly.</li>
</ol>

<p>The act of giving up your attachment is designed to leave you highly vulnerable - but also much more open to other perspectives and frames of reference. By definition, the more a certain idea is important to you, the harder it is to let go of attachment. Ego is a master of rationalization and to be honest some of its reasons are actually pretty logical and often valid, but in context of this practice all these rationalizations must be ignored, and all attachments must be let go. The exercise gets seriously difficult when it involves dealing with other people over different interests and perspectives, especially when this is a real life or work situation, <em>especially</em> when you are right - but this is exactly what makes this practice so effective. </p>

<p>The second exercise consists of your teacher occasionally pushing you to operate outside of your comfort zone. The normal student's reaction is to indulge in one's egoistic defenses until one day the student learns to get over them and open up to non-preconceptualized activity. This involves enormous creativity on the teacher's part, setting up all kinds of embarrassing situations in which the student is put on the spot and does not know how to react. It's hard to give specific examples since they tend to be very personal. A good Zen master or Vajra master has a talent for endless improvisation of these. The practice is both very painful and very effective for driving the student outside his or her preconceptualization.</p>

<p>In the absence of live teacher my advice is to get creative yourself and start finding ways to put yourself in situations when you do not have a good plan of action. Luckily, modern social life gives endless opportunities for trying one's luck outside one's comfort zone and watching oneself stumble.</p>

<p>Both of these exercises work by forcing the student to lay aside one's  preconceived notions, and practice operating in the preconceptual space of "beginner's mind".</p>

<p>It's seems awkward to explain all this in writing, as it is usually presented in a much more pithy and casual style in the middle of real life situations. Despite my limited ability to explain it with clarity, I can't overemphasize the importance of this practice. In my experience, it makes night-and-day difference in one's ability to comprehend and realize true Dharma. Hope it helps.</p>
 17133: <p>I've bumped into various prosaic and spiritual messages that have cultivated in me a certainty that most certainties are unjustified.</p>

<p>Studying debate in high school they drilled how to detect and avoid logical fallacies into us. It's easier to detect in the writing of others than your own, I find. If you can reliably detect them in your own thinking, you will cultivate a mental awareness that can help avoid these things. I could be wrong, but I think there's important elements of mindfulness involved with this process. I've found fallacies are used the most frequently when it comes to truths people don't want to face. </p>

<p>I'd not try to avoid speculation. I'd actually encourage it, especially when it comes to criticizing what's going on in your head. What information could you acquire, at least in principle, that would prove you wrong? Employ any criticisms you might offer to someone else to yourself. I suspect this facilitates taming Ego. The other side of the coin has similar effects. Have compassion for yourself as you have compassion for others. </p>

<p>Meditate. Watch your thoughts very carefully. What topics arise frequently in what order? Do you notice any patterns? You're likely to find there are some things you want to be true that might not be. That I suspect is the source of a lot of jumping to conclusions. </p>

<p>Do not seek perfection. Perfection is Ego lying to you. Don't get discouraged from meditating because your thoughts take a long time to settle. Don't think that you just can't do it. </p>

<p>These suggestions are heavily science/logic influenced, very linear. There's some problems stuck in thinking that way. I find Thich Nhat Hanh has a lot of great advice deviating from that pattern while cultivating understanding, especially in Zen Keys. He is very good at clarifying what information is being ignored when we try to contain things in our head with concepts. </p>

<p>Hope that helps!</p>
