The Torah’s prohibition against lying is formulated like this:
מדבר שקר תרחק
Distance yourself from words of untruth
Why not “Don’t lie”. Why not “Tell the truth”. There are a number of ways to look at this formulation:
- It’s saying, not only shouldn’t one lie, but one shouldn’t even come close. Don’t put yourself in position where you might wind up lying.
- Nobody is completely truthful. There can’t be a command to be completely truthful, or to completely avoid lying. But one can be enjoined to distance himself from untruth.
- Truth and falsehood are not binary categories; they are two poles on an axis, the one pole being ‘pure truth’, the other being ‘pure lie’. It’s impossible to really reach either pole. One can, however, work to distance himself from that pole and become closer to the other.
If it needs to be spelled out, I obviously prefer 2 or 3.