It must remain established, therefore, that reason--human reason--within its limits, not only does not prove rationally that the soul is immortal or that the human consciousness shall preserve its indestructibility through the tracts of time to come, but that it proves rather--within its limits, I repeat--that the individual consciousness cannot persist after the death of the physical organism upon which it depends. And these limits, within which I say that human reason proves this, are the limits of rationality, of what is known by demonstration. Beyond these limits is the irrational, which, whether it be called the super-rational or the infra-rational or the contra-rational, is all the same thing. Beyond these limits is the absurd of Tertullian, the impossible of the _certum est, quia impossibile est_. And this absurd can only base itself upon the most absolute uncertainty. The rational dissolution ends in dissolving reason itself; it ends in the most absolute scepticism, in the phenomenalism of Hume or in the doctrine of absolute contingencies of Stuart Mill, the most consistent and logical of the positivists. The supreme triumph of reason, the analytical--that is, the destructive and dissolvent--faculty, is to cast doubt upon its own validity. The stomach that contains an ulcer ends by digesting itself; and reason ends by destroying the immediate and absolute validity of the concept of truth and of the concept of necessity. Both concepts are relative; there is no absolute truth, no absolute necessity. We call a concept true which agrees with the general system of all our concepts; and we call a perception true which does not contradict the system of our perceptions. Truth is coherence. But as regards the whole system, the aggregate, as there is nothing outside of it of which we have knowledge, we cannot say whether it is true or not. It is conceivable that the universe, as it exists in itself, outside of our consciousness, may be quite other than it appears to us, although this is a supposition that has no meaning for reason. And as regards necessity, is there an absolute necessity? By necessary we mean merely that which is, and in so far as it is, for in another more transcendental sense, what absolute necessity, logical and independent of the fact that the universe exists, is there that there should be a universe or anything else at all? Absolute relativism, which is neither more nor less than scepticism, in the most modern sense of the term, is the supreme triumph of the reasoning reason. Feeling does not succeed in converting consolation into truth, nor does reason succeed in converting truth into consolation. But reason going beyond truth itself, beyond the concept of reality itself, succeeds in plunging itself into the depths of scepticism. And in this abyss the scepticism of the reason encounters the despair of the heart, and this encounter leads to the discovery of a basis--a terrible basis!--for consolation to build on.