Men talk learnedly nowadays of the human spirit, but with a doctrine which is often insufficient or, as we say, not up to date. They have stopped at one of those wayside concepts where thought no doubt passed and temporarily halted, but from which it moved on towards a more distant goal. For while this long history of the endeavours by which man struggles onward towards the understanding of his own nature is the basis on which modern philosophy builds its firm concept of the spirit, yet for those who have not attained the vantage ground of this modern philosophy, this history is unfortunately a very intricate maze; it is the bewildering "selva selvaggia ed aspra e forte"[3] from which it is difficult ever to issue. And therefore it is much easier, as Dante once remarked, to teach those who are completely ignorant than those who have a smattering of philosophy. But to-day culture is so intimately connected with philosophical speculation that the greater part of educated men profess this or that system without being aware of it. And when such men do take up the study of philosophy _per se_, they no longer possess the mental ingenuousness, the speculative candour, which would enable them to grasp the obvious, evident, incontrovertible truth of the most profound philosophical proposition. This inquiry then is difficult. It demands either a long, methodic, laborious study of the history of philosophy conducted with critical vigour, or that unyielding tenacity of the mind which is the surest sign of sound spiritual character; that steadfast firmness by which man, once in possession of a clearly irrefutable, truly fundamental truth, rigorously excludes from his soul all the allurements of prejudice, all convictions formerly entertained, even though extremely plausible, if they contradict his Truth. For he trusts that these perplexities, these difficulties which he is not now in condition to explain, will be removed in virtue of that very thought to which he has confidently committed himself. This unflinching resolve is the courage of the philosopher, who has never feared to brave common sense, and single-handed to marshal against the multitude the array of his seemingly absurd assertions, which however, in the progress of their reciprocal integrations, have subsequently contributed to redeem this very multitude from error,--from that error which is intellectual misery, social wretchedness, economic, political, and moral destitution. Because of this inflexible firmness the philosopher has never dreaded that boundless solitude, that thin atmosphere to which he is uplifted by thought, and where at first he has the sensation of fainting away into the rarefied air.