The inability to recover functions lost after severe spinal cord injury has been recognized for millennia and was first attributed to a failure of spinal cord neural regeneration over 100 years ago. The last forty years have seen intense research into achieving such regeneration, but in spite of conceptual advances and many reports announcing successful interventions, progress has been slow and often controversial. Here, I examine consequential advances and setbacks, and critically consider assumptions underlying certain approaches. I argue that expanding mechanistic knowledge about multiple forms of neural regeneration, why they fail and how they can restore function will resolve conceptual contentions and push the field forward.