It's because words are such effective tools of communication that we sometimes fail to realize how often we communicate without them. A conversation is sometimes a physical exchange. These conversations carry meaning that can only exist in the physical realm.
We signify to each other with words, with gestures, with emotional expressions. We also signify with commitments, with actions, and when this occurs (as it constantly does in our everyday lives) we are able to see that logical meaning is itself a physical thing. We can't say what we want to say without putting our bodies into it.
For example: my wife and I go to a wedding of a friend of hers who we haven't seen in a while. We both like the bride and groom a lot, and we used to enjoy hanging out with them, but tonight we barely get to talk to the marrying couple because they are so busy running around being the bride and groom. Still, we are glad we came to the wedding, because we are able to express something to the couple by being there. They know that we are there because we want to celebrate their marriage, and this recognition (which might not take place till weeks later when they see their wedding photos) amounts to a happy conversation that could not have been carried out if we were not there. We could have sent a card, and the card could have had many more words on it than we had a chance to speak. But the card would have expressed not more meaning but less than we expressed by being there.