Who is this author Forbes?

Forbes (1888) writes about God's "original purpose, the restoration of the race to the eternal life which they had forfeited, and to the primitive righteousness from which they had fallen". 

[Not righteousness, John, but naivety and innocence, and not to be sought as a restoration of state from the knowledge of good and evil. There is no escaping that knowledge, once acquired, and there is no doubt that humanity had it in the beginning, or as soon as that reflective state of consciousness and resonant memory was reached that enabled the human to grasp.]

Here is an Aberdeen man of the 19th century, a divine, telling the world about God's original purpose. Not too presumptuous, eh? Well, I guess I understand presumption myself.

Mr. John Forbes was not that easy to find on Google. The ancient sources in the archive have quite a few Forbes. But this professor of oriental languages, Aberdeen, does turn up occasionally, the second son of Patrick Forbes of Corss, bishop of Aberdeen. His brother William died without succession so John became the Laird of Corss. He married a Dutch woman who did bear to him George Forbes of Corss. (From a genealogy of the Family of Forbes - page 22.) In this same document we read many pages of people named John Forbes in the period. Where, I wonder did he get his degrees? How was he raised by his bishop father? He appears to have written a pamphlet:

on the reformation in Germany. It was a part of a series of Lectures on Foreign Churches, Delivered in Edinburgh and Glasgow, 1846, in connexion with the objects of the Committee of the Free Church of Scotland, on the State of Christian Churches on the Continent and in the East. You can buy it for 4s. 6d., cloth binding.

He is also a trained mathematician, having written a book on the Differential and Integral Calculus, "derived synthetically from an original principle." 

There is a delightful description of him in Our Scottish Clergy, Fifty-two Sketches. The author, a certain John Smith, begins with what might be read as praise, but soon pillories John Forbes:

You will find the article here.

Here is his educational background: