I am preparing a book for publication which contains the following passage:
Stromberg in Religious Liberalism in Eighteenth-Century England (1954) noted that 'the critical moment in the emergence of a positive spirit of reform...consisted in the awareness of evil as being social and remediable. It begins about 1750.
My proof reader (my wife) has picked this out suggesting it should be the past tense. However if I say It began about 1750 it seems to convey too much certainty about the exact date. I just want to convey an impression of it being something which emerges in the mid-eighteenth century. I believe use of the present tense is the way to go.
But what is this artifice called, this use of the present to convey mild uncertainty?