Bill,

Thank you for that thoughtful essay on the basis for structural
mechanics. It was well written and I agree with the principles you
outline. Although my structural mechanics may be a little rusty through
lack of use, I did study it to second year university level, and other
branches of mechanics to a higher level. I do consider myself to have a
good understanding of Newton's laws, free body diagrams, etc. In your
500+ words you have still not explained precisely why my free body
diagram is wrong. If it's wrong, I want to know why.

Chris