Yet even this modest claim must be deemed excessive: for the speculation on which it rests does violence to its own principles. Manifestly we cannot indulge ourselves in reflections upon the limits of the “knowable” without using our intellect for a purpose never contemplated by selection. I do not allege that our intellect is therefore unequal to the task. I only say that, if it be indeed equal to it, we are in the presence of a very surprising coincidence. Why should faculties, “designed” only to help primitive man, or his animal progenitors, successfully to breed and feed, be fitted to solve philosophic problems so useless and so remote? Why, indeed, do such problems occur to us? Why do we long for their solution? To such questions Naturalism can neither find an answer nor be content without one. Wearied with unavailing efforts to penetrate the unknown, many not ignoble spirits have preached the wisdom of dulling unhealthy curiosity by the aid of healthy labour. “Let us cultivate our gardens” (they say), seeking no solution of the insoluble. But the advice is ambiguous. Will the proposed remedy, in their opinion, cure the ill, or only help us to forget it? If the latter, then, in some circumstances and with some patients, it will doubtless fulfil its promise. Oblivion may be attained by growing vegetables, as by other less reputable expedients. But if absorption in daily labour be recommended as the final stage of a rational cure, it cannot be effectual. No rational cure is, on naturalistic principles, within our reach. Could we empty ourselves of all that makes us men, could we lower our intellectual level to the point where the scope of our mental activities harmonised with their naturalistic source, we should doubtless free ourselves from the malady of vain speculation. But though the remedy, if applied, would be effectual, it would not be rational. Reflective Agnosticism cannot be combined with scientific Naturalism, because reflective Agnosticism is the product of a process which Naturalism inevitably discredits. And if Naturalism be incompatible even with reasoned ignorance, how can we hope to harmonise it with the claims of reasoned knowledge?[16]