But the rationalists who talk of claim and obligation expressly say that they have nothing to do with our practical interests or personal reasons.  Our reasons for agreeing are psychological facts, they say, relative to each thinker, and to the accidents of his life.  They are his evidence merely, they are no part of the life of truth itself.  That life transacts itself in a purely logical or epistemological, as distinguished from a psychological, dimension, and its claims antedate and exceed all personal motivations whatsoever.  Tho neither man nor God should ever ascertain truth, the word would still have to be defined as that which ought to be ascertained and recognized.

There never was a more exquisite example of an idea abstracted from the concretes of experience and then used to oppose and negate what it was abstracted from.

Philosophy and common life abound in similar instances.  The ‘sentimentalist fallacy’ is to shed tears over abstract justice and generosity, beauty, etc., and never to know these qualities when you meet them in the street, because there the circumstances make them vulgar.  Thus I read in the privately printed biography of an eminently rationalistic mind:  “It was strange that with such admiration for beauty in the abstract, my brother had no enthusiasm for fine architecture, for beautiful painting, or for flowers.”  And in almost the last philosophic work I have read, I find such passages as the following:  “Justice is ideal, solely ideal.  Reason conceives that it ought to exist, but experience shows that it can-not. ...  Truth, which ought to be, cannot be. ...  Reason is deformed by experience.  As soon as reason enters experience, it becomes contrary to reason.”

The rationalist’s fallacy here is exactly like the sentimentalist’s.  Both extract a quality from the muddy particulars of experience, and find it so pure when extracted that they contrast it with each and all its muddy instances as an opposite and higher nature.  All the while it is their nature.  It is the nature of truths to be validated, verified.  It pays for our ideas to be validated.  Our obligation to seek truth is part of our general obligation to do what pays.  The payments true ideas bring are the sole why of our duty to follow them.

Identical whys exist in the case of wealth and health.  Truth makes no other kind of claim and imposes no other kind of ought than health and wealth do.  All these claims are conditional; the concrete benefits we gain are what we mean by calling the pursuit a duty.  In the case of truth, untrue beliefs work as perniciously in the long run as true beliefs work beneficially.  Talking abstractly, the quality ‘true’ may thus be said to grow absolutely precious, and the quality ‘untrue’ absolutely damnable:  the one may be called good, the other bad, unconditionally.  We ought to think the true, we ought to shun the false, imperatively.