With reference to Dr. West's position on the doctrine of the Trinity, his granddaughter, Mary C. West, of Tiverton, (recently deceased,) wrote in a communication printed in the Evening Standard of this city in March, 1883, as follows: "If his children were competent witnesses (my father and aunt) I can say that they have often told me that their father was an Arminian Unitarian. * * * I have heard my aunt many times tell this story. When she was a little girl her teacher set her to learning a catechism, — I think it was the Westminster, but at any rate it had the Trinitarian formula in it: 'The Father, the Son, and the Holy Ghost, and these three are one.' She was at home studying her lesson in a loud voice, and her father heard her repeating the above formula and called her to him and held up three of his fingers (as she always did when she told the story), and asked her how three could be one, took the book from her and put it in his pocket, and told her to tell her teacher that he would get her another catechism, which he did. I think the one he got her was called 'The Franklin Catechism,' or 'The Franklin Primer."
I've heard it noted that because Rev. West believed Christ as redeemer who made an atonement, that means he was orthodox. Wrong. That's a logical error called a "non-sequitur" -- a conclusion that does not follow from the facts presented. Some unitarians did believe in the resurrected Christ who made an atonement for man. Mormons and Jehovah's Witnesses believe this. They just hold an unconventional view of these doctrines. This fits perfectly with West's Arianism.
As the same above linked to source notes:
In theology, Dr. West was progressive and liberal. His sympathies with humanity were too quick to make him a good Calvinist. Judged by to-day's standards, much of his writing would seem antiquated. His sermons were largely of the old Biblical and textual type. But judged by his own time he was an Arminian, which was the transition passage to Unitarianism. That is, he asserted free will for man in opposition to Calvin's doctrine of fore-ordination and irreparable election, and man's ability of moral choice in opposition to the doctrine of "total depravity." With regard to Christ his views were more Arian than Athanasian....