user-1: I had previously asked a question about lying in fiction, but I feel I had omitted some important elements which I recently realized. I often write theoretical statements I am unsure of.

Does writing (not fiction) something untrue in itself, even if not shown or deleted, cause one to have uttered a lie? 
Does speculation about something, where ideas are asserted without certainty, consist in lying as well?

I am mainly asking because I had recent intuitions that the way I wrote could be a form of lying, and that symptoms in myself -- such as inconsistency and great uncertainty -- could perhaps be linked to this form of false-like expression. Since the Buddha advised against lying even in jest, I wonder if my expression's closeness to lying is detrimental. 
Thank you.

user-1: 
Does writing (not fiction) something untrue in itself, even if not
  shown or deleted, cause one to have uttered a lie?

Writing fiction and non-fiction text is not bad if your intention for writing is pure and with accordance to Buddhist ethics and precepts. Example, if your end goal isn't deception of the audience or personal gain, or lust - writing is fine. There is Buddhist art, poetry, stories and many architectonically beautiful temples which are also pieces of art. You shouldn't get carried away by signs in Buddhism, but you should also use them skilfully. There is the Chinese phrase of seeing the mountain, not seeing the mountain and then seeing the mountain again.
There are statues of Buddha and paintings that arouse great joy when needed, and that is definitely not negative. Ajahn Sumedho in his Four Noble Truths wrote that we shouldn't be those nagging old people that deny woman's beauty because its the fruit of conceptual mind - instead, we should marvel in women's beauty, there is vast ocean of multitude of shapes and that is joy.

Does speculation about something, where ideas are asserted without
  certainty, consist in lying as well?

If you presume that there will be no rain today, your are not doing anything strictly negative. So, speculation is not per se negative, but it is not the idea of Buddhism. Lack of complete knowledge is not lying, it is unintentional. There is in fact, numerous Buddhists among Physics community. All we do in Buddhism in the end is spiritual pursuit born of not knowing and wanting to find out. We do not know how it is at the end of the road, we can only guess. On absolute truth, Buddha said that any speculation of finding the absolute is not within the scope of Buddhism. Also, Buddhism doesn't have a take on standards and political organisation of society either, or crime and punishment in society, etc. Such speculations and ideas are beyond Buddhist's scope, though many Buddhists embrace feminism, vegetarianism - and many not.

user-1: ...and that symptoms in myself -- such as inconsistency and great uncertainty -- could perhaps be linked to this form of false-like expression
Not an answer to your exact question but an answer to your overall dilemma. I see you are worried that, there are some karmic repercussions to your possible act of lying. 
I would like to point out that Buddha advised,'Samma Vacca' if you read the whole page you will know that outright 'lying' is not advised but mainly the gist of Buddha's words is 'beneficial and wholesome speech which do not cause harm and suffering to others as well as your self'. 
Now an imaginary scenario which I read in the book 'Buddhism: Plain and Simple', suppose you have your friends hiding in the basement of your house and an SS officer knocks at your door and asks if you have anyone hiding in your house. Now, what will incur more bad Karma on you? outright lying to SS or handing over your friends by telling the truth? 
The ways of the Karma are very complex, it's not a linear cause-effect relationship. 
In summary what I am trying to say is, don't worry about the trivia, the path to Nibbana has to be balanced between many things 'Right Speech' being one amongst them. 
Remember Buddha advised 'Middle way' above all, so don't get paralyzed by travelling to extremes of moral behaviour. 

-1: <p>I had previously asked a question about lying in fiction, but I feel I had omitted some important elements which I recently realized. I often write theoretical statements I am unsure of.</p>

<ol>
<li>Does writing (not fiction) something untrue in itself, even if not shown or deleted, cause one to have uttered a lie? </li>
<li>Does speculation about something, where ideas are asserted without certainty, consist in lying as well?</li>
</ol>

<p>I am mainly asking because I had recent intuitions that the way I wrote could be a form of lying, and that symptoms in myself -- such as inconsistency and great uncertainty -- could perhaps be linked to this form of false-like expression. Since the Buddha advised against lying even in jest, I wonder if my expression's closeness to lying is detrimental. </p>

<p>Thank you.</p>
 -1: <blockquote>
  <p>Does writing (not fiction) something untrue in itself, even if not
  shown or deleted, cause one to have uttered a lie?</p>
</blockquote>

<p>Writing fiction and non-fiction text is not bad if your intention for writing is pure and with accordance to Buddhist ethics and precepts. Example, if your end goal isn't deception of the audience or personal gain, or lust - writing is fine. There is Buddhist art, poetry, stories and many architectonically beautiful temples which are also pieces of art. You shouldn't get carried away by signs in Buddhism, but you should also use them skilfully. There is the Chinese phrase of seeing the mountain, not seeing the mountain and then seeing the mountain again.</p>

<p>There are statues of Buddha and paintings that arouse great joy when needed, and that is definitely not negative. Ajahn Sumedho in his Four Noble Truths wrote that we shouldn't be those nagging old people that deny woman's beauty because its the fruit of conceptual mind - instead, we should marvel in women's beauty, there is vast ocean of multitude of shapes and that is joy.</p>

<blockquote>
  <p>Does speculation about something, where ideas are asserted without
  certainty, consist in lying as well?</p>
</blockquote>

<p>If you presume that there will be no rain today, your are not doing anything strictly negative. So, speculation is not per se negative, but it is not the idea of Buddhism. Lack of complete knowledge is not lying, it is unintentional. There is in fact, numerous Buddhists among Physics community. All we do in Buddhism in the end is spiritual pursuit born of not knowing and wanting to find out. We do not <em>know</em> how it is at the end of the road, we can only guess. On absolute truth, Buddha said that any speculation of finding the absolute is not within the scope of Buddhism. Also, Buddhism doesn't have a take on standards and political organisation of society either, or crime and punishment in society, etc. Such speculations and ideas are beyond Buddhist's scope, though many Buddhists embrace feminism, vegetarianism - and many not.</p>
 -1: <p><strong>...and that symptoms in myself -- such as inconsistency and great uncertainty -- could perhaps be linked to this form of false-like expression</strong></p>

<p>Not an answer to your exact question but an answer to your overall dilemma. I see you are worried that, there are some karmic repercussions to your possible act of lying. </p>

<p>I would like to point out that Buddha advised,'<em><a href="https://www.accesstoinsight.org/ptf/dhamma/sacca/sacca4/samma-vaca/" rel="nofollow noreferrer">Samma Vacca</a></em>' if you read the whole page you will know that outright 'lying' is not advised but mainly the gist of Buddha's words is 'beneficial and wholesome speech which do not cause harm and suffering to others as well as your self'. </p>

<p>Now an imaginary scenario which I read in the book 'Buddhism: Plain and Simple', suppose you have your friends hiding in the basement of your house and an SS officer knocks at your door and asks if you have anyone hiding in your house. Now, what will incur more bad Karma on you? outright lying to SS or handing over your friends by telling the truth? </p>

<p>The ways of the Karma are very complex, it's not a linear cause-effect relationship. </p>

<p>In summary what I am trying to say is, don't worry about the trivia, the path to Nibbana has to be balanced between many things 'Right Speech' being one amongst them. </p>

<p>Remember Buddha advised '<a href="https://en.wikipedia.org/wiki/Middle_Way" rel="nofollow noreferrer">Middle way</a>' above all, so don't get paralyzed by travelling to extremes of moral behaviour. </p>
