Olaf Stapledon said this quote

Philosophy is an amazing tissue of really fine thinking and incredible, puerile mistakes. It's like one of those rubber 'bones' they give dogs to chew, damned good for the mind's teeth, but as food - no bloody good at all.

~ Olaf Stapledon

There is much in this vision that will remind you of your mystics; yet between them and us there is far more difference than similarity, in respect both of the matter and the manner of our thought. For while they are confident that the cosmos is perfect, we are sure only that it is very beautiful. While they pass to their conclusion without the aid of intellect, we have used that staff every step of the way. Thus, even when in respect of conclusions we agree with your mystics rather than your plodding intellectuals, in respect of method we applaud most your intellectuals; for they scorned to deceive themselves with comfortable fantasies.

~ Olaf Stapledon

Sitting there on the heather, on our planetary grain, I shrank from the abysses that opened up on every side, and in the future. The silent darkness, the featureless unknown, were more dread than all the terrors that imagination had mustered. Peering, the mind could see nothing sure, nothing in all human experience to be grasped as certain, except uncertainty itself; nothing but obscurity gendered by a thick haze of theories. Man's science was a mere mist of numbers; his philosophy but a fog of words. His very perception of this rocky grain and all its wonders was but a shifting and a lying apparition. Even oneself, that seeming-central fact, was a mere phantom, so deceptive, that the most honest of men must question his own honesty, so insubstantial that he must even doubt his very existence.

~ Olaf Stapledon

For the former, activity, any kind of activity, was an end in itself; for the latter, activity was but a progress toward the true end, which was rest, and peace of mind. Action was to be undertaken only when equilibrium was disturbed.

~ Olaf Stapledon