The Sword Polisher's Record p 58 by Adam Hsu
Internal and external do not represent different styles or kinds of kung-fu, but rather different levels.
through rumors, jealousies, and rivalries, many confusing and contradictory viewpoints concerning internal and external spread.
When kung-fu came to America, students adopted many of their instructors' prejudices and misconceptions. In many cases, by not clearly understanding the use of internal and external in Chinese culture, students began to create their own explanations as to what the differences were. Needless to say, this added to an already confusing and unclear situation.
I believe that all these internal/external theories are in fact quite incorrect. The distinction is really very simple to understand. Internal and external do not represent different styles or kinds of kung-fu, but rather different levels. We can say that the external represents the lower or more elementary level of kung-fu, and the internal the higher and more complex.
Therefore in real kung-fu training, regardless of the style, one must begin from the external and patiently and systematically progress inward to the internal.
Since some instructors were unable to complete the entire training in their particular styles, many systems today are incomplete and never go beyond the external level. If practitioners are carefully guided by an honest and qualified teacher, who went through the complete training in a certain style, they will move step-by-step from the outside, through the door, climb upstairs to the top level, and then reach the internal-the highest level of kung-fu.