"Interwoven with the very rudiments of Christianity": Horsley's praise for Calvin

From Horsley's Charge to the Clergy of the Diocese of St Asaph, 1806, addressing what he terms "the Calvinistic controversy:

But if ever you should be provoked to take a part in these disputes, of all things I entreat you to avoid, what is now become very common, acrimonious abuse of Calvinism and of Calvin. Remember, I beseech you, that some tenderness is due to the errors and extravagancies of a man eminent as he was in his day for his piety, his wisdom, and his learning, and to whom the Reformation in its beginnings is so much indebted. At least take especial care, before you aim your shafts at Calvinism, that you know what is Calvinism and what is not, - that in that mass of doctrine which it is of late become the fashion to abuse under the name of Calvinism, you can distinguish with certainty between that part of it which is nothing better than Calvinism, and that which belongs to our common Christianity and the general faith of the Reformed Churches; lest, when you mean only to fall foul of Calvinism, you should unwarily attack something more sacred and of higher origin. I must say, that I have found great want of this discrimination in some late controversial writings, on the side of the Church, as they were meant to be, against the Methodists; the authors of which have acquired much applause and reputation, but with so little real knowledge of their subject, that give me the principles upon which these writers argue, and I will undertake to convict - I will not say Arminians only and Archbishop Laud - but upon these principles, I will undertake to convict the fathers of the Council of Trent of Calvinism: So closely is a great part of that which is now ignorantly called Calvinism interwoven with the very rudiments of Christianity.