The Torah’s demand for two witnesses carries many important implications about law, jurisprudence and truth. The most obvious is that the bar for the conviction of criminals is set much higher than in most contemporary systems of law, that accept the testimony of one witness. On one foot, that means that the Torah prefers to let several criminals off, rather than have one innocent man punished.
But moving on to a more philosophical level, the Torah also teaches us how private information becomes communal. What I mean is that there are many things that every individual knows for themselves. We know what we have seen, felt, tasted and thought – just to mention a few of the ways we experience things. But if no one else has experienced the same thing, all of these still remain subjective. This does not mean that they are any less true. What it does mean is that there is no standard by which the community can evaluate them. Once an experience is shared by more than one person, however, it moves into the realm of the communal. Since for two people to have experienced the same thing means that we have some guideline through which the information can now be verified. Indeed, Jewish laws primarily tests witnesses against each other.
The above is easy to understand and most reasonable. But lest we get too smug, Netziv (17:6) brings in a nuance which complicates matters. Based on the Yerushalmi and on an observation about the word shnayim (two, as opposed to the more grammatically appropriate, shnei, two of), he tells us that if the words of the two witnesses are overly identical, it is grounds to suspect them.
Netziv bases himself on another place the Torah uses the word shnayim, this time with reference to the keruvim on top of the ark (Shemot 25:18). Along with Rabbenu Bachya, he understands this to be a hint to the fact that they were not exactly the same, but that one was in the shape of a male and the other in the shape of a female. Hence the idea that what makes them different is actually also what makes them one (at least potentially). Though neither commentary mentions it, this seems to be explicitly based on Bereshit 2:24 which speaks about the potential of man and woman to become one flesh. It is not just that the anatomies of a man and a woman can come together – it is more profoundly that when they do, they create one reproductive organism. Out of two, they literally become one.
Since Netziv adapted the above idea to he less obvious arena of testimony, it seems that he is setting up the similar-yet-different keruvim as a model for any productive group of more than one person. In other words, were two people to be exactly alike, they would not add anything to each other. It is obvious that two people have to come to agreements about most things within any given project in order to work together. What is new here is that if they agree about everything, their cooperation ends up being ultimately worthless. Today if it is just ‘an extra pair of hands’ that is needed, one may as well find a computer… or a clone. But for two people to actually create anything worthy of their partnership, it will only be because they have expressed their complementary differences, as well as their similarities. Indeed, we know from experience that the most productive partnerships are when people bring different strengths to the table, and not just the same ones.
Surprisingly, this is even true of two witnesses. When we are using one as a control for the reliability of the other, the second person really has to be someone else. But if two people constantly experience the same thing, we do not even need to bring them to court to know that they will tell us the same thing. For it is not two witnesses in front of us but rather one witness and his clone.
Going from one to two – from the private to the communal – is one of the most complicated and interesting processes in human existence. Working with others literally opens up a world of possibilities. But for that to happen two things must be present – similarity and difference.