Read two sentences from the exposition of the motto of Fudan University by its first President, Dr. Wen, "Know something in everything" and "Know everything in something", which seem to be quite true. I search for their source, but could not find one. The closest I can get is an anonymous quote "A Ph.D. is one who knows everything about something and knows something about everything". Indeed, a successful Ph.D. must have breadth in knowledge (know something in everything), but also depth (know everything in something). Without breadth, research findings will have limited impact and researchers would lose any vision on what has been discovered. Without depth, one would not get solid work done and research findings would be just superficial. Thus, a Ph.D. student needs to work on both.