Epictetus, Golden Sayings 13

But God has introduced Man to be a spectator of Himself and of His works, and not a spectator only, but also an interpreter of them. Wherefore it is a shame for man to begin and to leave off where the brutes do. 

Rather he should begin there, and leave off where Nature leaves off in us, and that is at contemplation, and understanding, and a manner of life that is in harmony with Herself. 
  
See then that you die not without being spectators of these things.