The error involved in attributing value to the past is naturally aggravated when values are to be assigned to the future. In the latter case imagination cannot be controlled by circumstantial evidence, and is consequently the only basis for judgment. But as the conception of a thing naturally evokes an emotion different from that involved in its presence, ideals of what is desirable for the future contain no warrant that the experience desired would, when actual, prove to be acceptable and good. An ideal carries no extrinsic assurance that its realisation would be a benefit. To convince ourselves that an ideal has rational authority and represents a better experience than the actual condition it is contrasted with, we must control the prophetic image by as many circumlocutions as possible. As in the case of fame, we must buttress or modify our spontaneous judgment with all the other judgments that the object envisaged can prompt: we must make our ideal harmonise with all experience rather than with a part only. The possible error remains even then; but a practical mind will always accept the risk of error when it has made every possible correction. A rational will is not a will that has reason for its basis or that possesses any other proof that its realisation would be possible or good than the oracle which a living will inspires and pronounces. The rationality possible to the will lies not in its source but in its method. An ideal cannot wait for its realisation to prove its validity. To deserve adhesion it needs only to be adequate as an ideal, that is, to express completely what the soul at present demands, and to do justice to all extant interests. CHAPTER XI—SOME ABSTRACT CONDITIONS OF THE IDEAL [Sidenote: The ultimate end a resultant.] Reason’s function is to embody the good, but the test of excellence is itself ideal; therefore before we can assure ourselves that reason has been manifested in any given case we must make out the reasonableness of the ideal that inspires us. And in general, before we can convince ourselves that a Life of Reason, or practice guided by science and directed toward spiritual goods, is at all worth having, we must make out the possibility and character of its ultimate end. Yet each ideal is its own justification; so that the only sense in which an ultimate end can be established and become a test of general progress is this: that a harmony and co-operation of impulses should be conceived, leading to the maximum satisfaction possible in the whole community of spirits affected by our action. Now, without considering for the present any concrete Utopia, such, for instance, as Plato’s Republic or the heavenly beatitude described by theologians, we may inquire what formal qualities are imposed on the ideal by its nature and function and by the relation it bears to experience and to desire. [Sidenote: Demands the substance of ideals.]