The issue focused on the position of "What is the object of each kind of physical investigation?" and is then followed by a comment on the object of this particular study. (The former is more likely to be found in a review of the general approach to the study of natural selection, and the latter in a review of the field of evolution and its associated studies.)

The question of what is the object of every kind of physical investigation is in some sense a question of what is the object of an investigation.