Their purpose is to "promote and diffuse the study of natural theology in the widest sense of the term – in other words, the knowledge of God."
Besides a general audience, the Lecturer may form a special class of students for the study of the subject, which will be conducted in the usual way, and tested by examination and thesis, written and oral".
[5] The lectures are normally presented as a series over an academic year and given with the intent that the edited content be published in book form.
A number of these works have become classics in the fields of theology or philosophy and the relationship between religion and science.
In 1889, those attending the Gifford Lectures at the University of St Andrews were described as "mixed" and included women as well as male undergraduates.