  I start with a historical review of the attempts to construct theories for
the origin of nuclear forces, for which I also summaries the most important
properties. The review then shifts to its main focus, which is the chiral
effective field theory approach to nuclear forces. I summarize the current
status of this approach and discuss the most important open issues: the proper
renormalization of the chiral two-nucleon potential and sub-leading
three-nucleon forces.
