Herbert of Cherbury

Another fascinating 17th century British (Welsh) intellectual was Edward Herbert, 1st Baron Herbert of Cherbury (and brother of the poet George Herbert), a fighter, courtier, diplomat, historian and philosopher.

In addition to an adventurous life, Herbert, who was educated at Oxford, published a treatise entitled De Veritate, or, On Truth, as It Is Distinguished from Revelation, the Probable, the Possible, and the False.

According to The defence of truth, Herbert of Cherbury and the senveteenth century, Herbert's first proposition is "Truth exists."

"The sole purpose of this proposition," Herbert goes on to say, "is to assert the existence of truth against imbeciles and sceptics (contra insanos & Scepticos)." Herbert was not so much interested in asserting some absolute truth as investigating the method and conditions by which we can possess certain knowledge. This would lead to his developing a notion of "natural instinct," which is likely akin to the "light of nature" that was a commonplace of humanists, including the Cambridge Platonists.

Herbert was a kind of British Descartes, throwing out all previous philosophic efforts to pin down truth in order to begin anew. It led to some interesting and suggestive notions, as this article notes:

Herbert's doctrine of the nature of truth rests on this conception of harmony. "Truth," he says, "is a certain harmony between objects and their analogous faculties."

Herbert's notion of how the mind relates to the world has been linked to later "Common Sense" schools of thinking, and he's been called "the father of English Deism," a theology which would emerge more fully during the Enlightenment.

Interestingly De Veritate was first published in Paris, in 1624, and Mersenne, one of Descartes' closest confidants and defenders, translated it into French and sent it to the French philosopher, who eventually responded by saying, "he examines what truth is; for myself, I have never doubted about it, as it seems to me to be a notion so transcendentally clear that it is impossible to ignore it" (letter of Oct. 16, 1639). But the Frenchman goes on to say that he esteemed Herbert above "des esprits ordinaires." More here.