In Alexander work we learn the meaning of Alexander's four directions, which we need to think and not do. The meaning changes for us over time.
The directions help bring about, or restore, integrity in the relationship between head, neck and back. Without this, really there can be no integrity.
The directions, or 'orders' as Alexander called them, are thoughts, messages from our brain through our nervous system. Alexander used the phrase, in page 42 of The Use of the Self, 'all together, one after the other' to describe the process of giving directions.