The case is like a snowball’s growth, due as it is to the distribution of the snow on the one hand, and to the successive pushes of the boys on the other, with these factors co-determining each other incessantly.

The most fateful point of difference between being a rationalist and being a pragmatist is now fully in sight.  Experience is in mutation, and our psychological ascertainments of truth are in mutation—­so much rationalism will allow; but never that either reality itself or truth itself is mutable.  Reality stands complete and ready-made from all eternity, rationalism insists, and the agreement of our ideas with it is that unique unanalyzable virtue in them of which she has already told us.  As that intrinsic excellence, their truth has nothing to do with our experiences.  It adds nothing to the content of experience.  It makes no difference to reality itself; it is supervenient, inert, static, a reflexion merely.  It doesn’t exist, it holds or obtains, it belongs to another dimension from that of either facts or fact-relations, belongs, in short, to the epistemological dimension—­and with that big word rationalism closes the discussion.

Thus, just as pragmatism faces forward to the future, so does rationalism here again face backward to a past eternity.  True to her inveterate habit, rationalism reverts to ‘principles,’ and thinks that when an abstraction once is named, we own an oracular solution.

The tremendous pregnancy in the way of consequences for life of this radical difference of outlook will only become apparent in my later lectures.  I wish meanwhile to close this lecture by showing that rationalism’s sublimity does not save it from inanity.

When, namely, you ask rationalists, instead of accusing pragmatism of desecrating the notion of truth, to define it themselves by saying exactly what they understand by it, the only positive attempts I can think of are these two: 

1.  “Truth is just the system of propositions which have an un-conditional claim to be recognized as valid.” [Footnote:  A. E. Taylor, Philosophical Review, vol. xiv, p. 288.]

2.  Truth is a name for all those judgments which we find ourselves under obligation to make by a kind of imperative duty. [Footnote:  H. Rickert, Der Gegenstand der Erkenntniss, chapter on ’Die Urtheilsnothwendigkeit.’]

The first thing that strikes one in such definitions is their unutterable triviality.  They are absolutely true, of course, but absolutely insignificant until you handle them pragmatically.  What do you mean by ‘claim’ here, and what do you mean by ‘duty’?  As summary names for the concrete reasons why thinking in true ways is overwhelmingly expedient and good for mortal men, it is all right to talk of claims on reality’s part to be agreed with, and of obligations on our part to agree.  We feel both the claims and the obligations, and we feel them for just those reasons.