Forsyth entered Glasgow College at the age of fourteen, and obtained a license as a probationer of the Church of Scotland (a candidate for minister, serving a required probationary period).
The court ruled that to be admitted to the bar, Forsyth would have to resign his office of licentiate, but after he did so the Faculty continued to refuse his admission.
[3] With few prospects in the legal profession, Forsyth turned next to literature, and managed to make a living by writing for booksellers.
[3] Reflecting his varied professional experiences, Forsyth's chief works include Principles and Practice of Agriculture (2 vols.
This work was reviewed critically by Hugh Miller, then editor of the Witness, who ridiculed Forsyth's remarks in the pamphlet as well as some of his past speculations on philosophy (several of which bear similarities to commonly accepted current views).
For example, Forsyth once noted: "Whatever has no tendency to improvement will gradually pass away and disappear for ever", hinting at the now-commonplace concept of the survival of the fittest.