The selection of what is significant within the history of a subject and the reasons for such significance, and even what falls within the bounds of the subject whose history is being traced, must be affected by the author's current standpoint, in part at least the product of his own upbringing.

Such an approach may be deliberate and explicit, and is probably justified if the readership aimed at is wide … in that it provides a unifying and easily grasped viewpoint from which to interpret and assess the work of earlier generations; but it does reinforce the theme of unitary development. Earlier scholars are noticed, and commended or criticized according as they comply with working precepts in current favour and to the extent that a contemporary scholar can view their work without serious change in the attitude towards his subject. Persons, and the topics they discuss or expound, are selected for attention as “milestones” (notice the implications of this common metaphor) in the progress of the subject up to the present day.