Here is substance for an excellent ironical system of the universe, such as some philosopher in Greece might have espoused; a flux of absolute intensive existences, variously coloured and more or less warm, like the sparks of a rocket. Some scientific philosopher in our day or in the future may be tempted to work out this system, and it might have been the true one. But I see an objection to it from the point of view of British philosophy, which covets knowledge of fact. The philosopher conceiving this system, if the system was true, would be only one of those sparks; he could have no idea except the idea which he was; the whole landscape before him would be but the fleeting nature of himself. Although, therefore, by an infinitely improbable accident, his philosophy might be true, he could have no reason to think it true, and no possibility of not thinking it so. A genuine sceptic might be satisfied with this result, enjoying each moment of his being, and laughing at his own perpetual pretension of knowing anything further. And since extremes meet, such a mocking sceptic might easily become, like Plato, a lover of pure Ideas. If he really abandons all claims, all hopes, all memory which is more than fantasy, and simply enjoys the illusion of the moment, he dwells on an Idea, which is all that an illusion can supply. The immediate has a mystical charm; it unveils some eternal essence, and the extreme of renunciation, like a sacrificial death, brings a supreme security in another sphere. Berkeley and Hume were little more than boys when they fell in love with Ideas; perhaps, if we knew their personal history, we should find that they were little children when they first did so, and that pure Essence was the Beatrice that had secretly inspired all their lives. But though they were youths of genius, there was a touch in them of the prig; the immediate, dear as it is to fresh and honest hearts, was too unconventional for them legally to wed and to take home, as it were, to their worldly relations. In England to love Ideas is to sow one's intellectual wild oats. There may be something healthy and impetuous in that impulse which is engaging; but it must not go too far, and above all it must not be permanent. The British philosopher dips into idealism in order to reform belief, to get rid of dangerous shams or uncongenial dogmas, not for the sake of pure intuition or instant assurance. He wishes to remove impediments to action; he hates great remote objects as he hates popery and policy; imposing things are impositions. Better get rid, if possible, of substance and cause and necessity and abstractions and self and consciousness. The purpose is to reduce everything to plain experience of fact, and to rest neither in pure intuition nor in external existences. For instance, he has two arguments against the existence of matter which he finds equally satisfactory: one that matter cannot exist because he can form no idea