It’s not trial and error, it’s trial and observation. Error implies a failure, but the only failure is when truly nothing is gained. An error, in this way, is when the unexpected happens as a result of the trial, but nothing is learned. If nothing was learned, the trial would never change. Or if it did, the change would be random, directionless. Observation, however, of an unexpected result, is learning. It affords educated change. It provides the direction necessary for further learning, discovery and development. Observation precedes evolution.