For the honesty and the candor not only led him to admit his own mistakes, but made him singularly ready to recognize the merits of others, and to tolerate not only their views but even their dogmatic assertion of them. He made mistakes all the time, and yet he knew that he was sincere and lofty in purpose. Why should not others be the same? Why should not their theories be right and his wrong? ‘It matters very little to any one except myself, whether I am a little more or less wrong on this or that point; in fact, I am sure to be proved wrong on many points.’[85] Of one who did not agree with him he could say: ‘I know nothing of him excepting from his letters: these show remarkable talent, astonishing perseverance, much modesty, and what I admire, determined difference from me on many points.’[86] And how winning is his defense of blunderers, of those who do poor work which is not all poor: ‘Shall you think me very impudent if I tell you that I have sometimes thought that ... you are a little too hard on bad observers; that a remark made by a bad observer _cannot_ be right; an observer who deserves to be damned you would utterly damn. I feel entire deference to any remark you make out of your own head; but when in opposition to some poor devil, I somehow involuntarily feel not quite so much.’[87] The truth is, that Darwin’s tolerance was based, as all real tolerance is apt to be, on the vast and haunting sense of his own ignorance. Again and again he repeats and emphasizes how little he knows, how little any one knows, and how petty, imperfect, and inadequate are the efforts of any and all of us to penetrate the veil of shrouding mystery which involves the deepest secrets of life. To probe this mystery the vague and flickering torch of reason is all that is given to us. And those who are most conversant with reason and make most use of it mistrust it most. When the far surer guidance of instinct fails us, reason is our only support, and we must employ it not only for the larger speculative purposes, but for the practical decisions. At its best, it is a bright and splendid instrument, incredibly keen and penetrating, and able to accomplish miracles in the hands of those who manipulate it skillfully. But it is an instrument as delicate as it is bright, and it loses point and edge, unless constant pains are taken to keep it in working condition. Also, it cuts both ways, and every way, and to even the expert manipulator, perhaps to him most of all, it is apt to be difficult, dangerous, treacherous. There is the subtle, unfathomable connection of reason with our wishes, desires, and prejudices. A clever Frenchman said that reason was given us to enable us to justify the gratification of our passions, and when we see how the devices of logic may be used to work from any premises to any conclusion, one feels the force of the Frenchman’s view.