Study the past if you would define the future. I am not one who was born in the possession of knowledge; I am one who is fond of antiquity, and earnest in seeking it there. Learning without thought is labor lost; thought without learning is perilous.
If one learns from others, but does not think, one will be bewildered. If, on the other hand, one thinks but does not learn from others, one will be in peril.
In archery we have something like the way of the superior man. When the archer misses the center of the target, he turns round and seeks for the cause of his failure in himself.