The following is based on a drasha I gave on the occasion of my daughter Nitza's engagement. More about that later...
We read in Kohelet:
קהלת פרק ב (יג) וראיתי אני שיש יתרון לחכמה מן הסכלות כיתרון האור מן החשך:
Ecclesiastes Chapter 12 (13) And I saw that there is an advantage to wisdom over foolishness like the advantage of light over darkness.
The main theme of Kohelet is wisdom. While the author has many insights and anecdotes on the subject, the quote above encapsulates a basic notion presented in the book: Wisdom implies an awareness of what is actually happening while it is happening, just as one can see what's going on when there is light.
This sort of awareness has a central place in Jewish practice. For example, we read in the first Mishnah of the second chapter of B'rachot:
היה קורא בתורה והגיע זמן המקרא אם כיון לבו יצא ואם לאו לא יצא
(If) he was reading in the Torah and the time for reading (the Shma) arrived, if he directed his heart then he fulfilled (the mitzvah of Shma) and if not, he did not fulfill the (the mitzvah of Shma).
In other words, if one happened to be reading a Torah and happened to be reading the parshah of Shma at the time one is supposed to be fulfilling the mitzvah of reading the Shma, then if one had intention (כוונה , kavanna, literally 'directed his/her heart') then the mitzvah is fulfilled.
But what is meant by 'kavanna?'
The most obvious possibility (and the one assumed initially by the gemara here in Talmud Bavli B'rachot 13a) is the intention to fulfill the mitzvah of Shma.
This understanding indicates that the minimum intention required to fulfill a mitzva is cognizance that one is doing the mitzvah.
However, the gemara goes on to offer another possibility: Maybe the person wasn't exactly reading the Torah. Maybe he was just checking the Torah or checking one scroll against another to find any errors. Such 'reading' is not really reading the words as such with all the proper vocalization; it can be done (and I can attest to this as a scribe) by reading letters or reading words in such a way as to make sure all the letters are there.
With this understanding of the Mishnah, the kind of intention changes. Whereas in the first understanding the intention needed would be to fulfill the mitzvah of Shma, now it would be sufficient to read the words as they are written with proper vocalization. If one started off by reading merely to check the scroll and switched at the proper time to reading the words as they are supposed to be pronounced, even if he was unaware that he was performing a mitzvah, he would nonetheless fulfill the mitzvah.
At this point, based on the gemara's two possible understandings, we now have two levels of intention : Intention in the sense of being aware of the physical act of reading and intention in the sense of wanting to fulfill the mitzvah. The gemara is arguing that even the most minimal sense that one is reading the words of the Shma might be sufficient to fulfill that mitzvah.
While the gemara discusses aspects of this question later, I want to point out that the next Mishnah enlightens us about this question in a deeper way. The second Mishnah in the chapter states:
א"ר יהושע בן קרחה למה קדמה שמע לוהיה אם שמוע אלא כדי שיקבל עליו עול מלכות שמים תחלה ואחר כך יקבל עליו עול מצות
Rabbi Yehoshua ben Karcha says: Why does (the paragraph of) Shma precede (the paragraph of) V'haya Im Shamoa? In order that one first accepts upon themselves the yoke of heaven and afterward accepts upon themselves the yoke of the commandments.
Rabbi Yehosha ben Karcha's point here has halachic ramifications in that it explains why the order we read the paragraphs of the Shma is important.
Beyond that, though, we understand that the Rabbi is inviting us to embrace the reading of the Shma with meaning; a deeper meaning than is implied by the minimal requirements of the mitzvah to simply be aware of one's physical actions. Rather he is implying yet another level of kavanna: The awareness not only that one is reading words or even that one is fulfilling a mitzva, but the awareness of the meaning of one's actions.
Embracing this meaning comes as a result of the first two levels of kavanna.
I would offer that the point given here is a metaphor for our lives and part of what Kohelet is trying to teach us, as well.
To be truly wise, we must be aware on many levels of what we are doing, what is happening and what the results of our actions might be.
When I look at my daughters, Tirtzah and Nitza, who are now getting married, I can only be proud of them both for the kind of awareness and consideration which with they have imbued their actions. It is clear to me that each of them has carefully considered their partners and not only where they are now, but where they will be in the future. Marriage to them is not just an action to be cognizant of; it is a vital step in their respective lives.
They have chosen well. I wish them every blessing.