Oh, where to begin! Yes, James said this; no, it is not the case that James was stupid and it would be a travesty to dismiss James! But Lordy, have you stepped into a huge question- it is no wonder the Wiki-machine makes it sound so simplistic.
Scholars of James, Peirce, and Royce (to name a few) make their livelihoods debating this particular question and I think it safe to say that you will not find consensus among them. Heck, at a table of four James scholars, there will be at least 5 opinions! [A great James scholar I know answers any question about James' thought with the caveat "Well, it's very complicated."]
As a reader of classic American philosophy, with a deep regard for James, I confess I am at a loss to reply in simple terms - and will delight in the responses of others who go where I fear to tread. I am most familiar with Royce and therefore I offer this humble suggestion: if you wish to get a very quick course in James, you might start with his Lowell Lectures of 1907 called "Pragmatism." It is well worth the effort - and while it won't settle the status of truth for James, it might get you enticed into sorting through the question more ably as a worthy contribution to Wikipedia.