Reasonings and convictions which I deem natural and legitimate, he apparently would call irrational, enthusiastic, perverse, and immoral; and that, as I think, because he consults his own ideal of how the mind ought to act, instead of interrogating human nature, as an existing thing, as it is found in the world. Instead of going by the testimony of psychological facts, and thereby determining our constitutive faculties and our proper condition, and being content with the mind as God has made it, he would form men as he thinks they ought to be formed, into something better and higher, and calls them irrational and immoral, if (so to speak) they take to the water, instead of remaining under the narrow wings of his own arbitrary theory.
This is Newman writing in A Grammar of Assent about Locke on ‘Probability’ and ‘Enthusiasm’ in his Essay Concerning Human Understanding. ‘Grammar’ was completed in 1870 and it is interesting that W.K. Clifford in his well known Ethics of Belief published in 1877 offers the same view of assent that Locke does. Personally I am persuaded by the psychological force of Newman’s rebuttals and his discovery of contradiction in Locke. It is instructive to compare his view of our normal acceptance of incomplete demonstration to that which William James limns in The Will to Believe from 1896. In that essay is a picture of spiritual anguish and of forced assent that is far from healthy-minded.
In this short note I merely draw attention to a cluster of views occurring around the latter quarter of the 19th. century. It may be that the ascetic had the more penetrating analysis of the three.