Abstract
Changes in laboratory animal science in the 20 years since George Porter's death are reviewed, with particular emphasis on animal welfare. The need for a generally acceptable definition of animal welfare is emphasized and a new definition is propounded. The concept of stewardship as a basis for human-animal relationships is explored. This involves Man accepting his responsibility for his relationship with, and care of, animals while simultaneously accepting a moral responsibility to God, or others, for that care and relationship.