We have now attained to the theory of research, yet we cannot abandon the survey of the necessary forms of error without mentioning a new form which arises precisely from the confusion between truth and the search for the conditions preparatory to truth, between truth and hypothesis. This error, which converts Heuristic into Logic, may be called _hypothesism._ It asserts that in regard to truth man can do nothing more than propose hypotheses, which are said to be more or less probable, so that his fate is not dissimilar to the punishments which were assigned to Tantalus, Sisyphus, and the Danaids. But in the kingdom of the True, differently from that of Erebus: The birds do not feed, The wheels do not turn, The stone is not rolled up the high mountain, Nor water drawn with the sieve from the fountain. The hypothesis is made, because it serves toward the attainment of the truth; did it not serve this end it would not be made. The spirit does not admit waste of time; for it time is always money. Hypothesism is sometimes restricted to the supreme principles of the real, or to what is called metaphysics, which would thus be always hypothetical; but for the reasons given in our discussion of agnosticism, if the principles of the real were hypothetical, the whole truth would be so, that is to say, there would not be any truth. For the rest, hypothesism, besides being internally contradictory, openly reveals that it is so, in its reference to the greater or lesser _probability_ of hypotheses. It would be impossible to determine the degree of approximation to the true without presupposing a criterion of truth, a truth and consequently the truth. We should hardly have made mention of this error did it not constitute the fulcrum of some of the most celebrated and revered philosophies of our times. VII THE PHENOMENOLOGY OF ERROR AND THE HISTORY OF PHILOSOPHY [Sidenote: _Inseparability of the phenomenology of error from the philosophic system. _] The phenomenology of error, in its double sense of error and of suggestion, coincides therefore with the philosophic system. Both error and suggestion are improper combinations of philosophic ideas or concepts. To determine these improper combinations is equivalent to showing the _obverse_ of that of which the philosophic system is the _face._ But face and obverse are not separable, for they constitute a single thought (and single reality), which is positivity-negativity, affirmation-negation. There is, therefore, no phenomenology of error outside the philosophic system, nor a philosophic system outside the phenomenology of error; the one is conceived at the moment when the other is conceived. And since the philosophic system and the doctrine of the categories are the same, the phenomenology of error is inseparable and indistinguishable from the doctrine of the categories. [Sidenote: _The eternal going and coming of errors._]