In general, I think my critics attribute to me more illusions than I have. My dogmatism may be a fault of temper or manner, because I dislike to stop to qualify or to explain everything; but in principle it is raised more diffidently and on a deeper scepticism than most of the systems which are called critical. My "essences," for instance, are blamed for being gratuitous inventions or needless abstractions. But essences appear precisely when all inventions are rescinded and the irreducible manifest datum is disclosed. I do not ask any one to _believe_ in essences. I ask them to reject every belief, and what they will have on their hands, if they do so, will be some essence. And if, believing nothing, they could infinitely enlarge their imagination, the whole realm of essence would loom before them. This realm is no discovery of mine; it has been described, for instance, by Leibniz in two different ways; once as the collection of all possible worlds, and again as the abyss of non-existence, _le néant_, of which he says: "The non-existent ... is infinite, it is eternal, it has a great many of the attributes of God; it contains an infinity of things, since all those things which do not exist at all are included in the non-existent, and those which no longer exist have returned to the non-existent." It suffices, therefore, that we deny a thing for us to recognize an essence, if we know at all what we are denying. And the essence before us, whether we assert or deny its existence, is certainly no abstraction; for there is no other datum, more individual or more obvious, from which the abstraction could be drawn. The difficulty in discerning essences is simply the very real difficulty which the practical intellect has in abstaining from belief, and from everywhere thinking it finds much more than is actually given. Profound scepticism is favourable to conventions, because it doubts that the criticism of conventions is any truer than they are. Fervent believers look for some system of philosophy or religion that shall be _literally_ true and worthy of superseding the current assumptions of daily life. I look for no such thing. Never for a moment can I bring myself to regard a human system--a piece of mental discourse--as more than a system of notation, sometimes picturesque, sometimes abstract and mathematical. Scientific symbols, terms in which calculation is possible, may replace poetic symbols, which merely catch echoes of the senses or make up dramatic units out of appearances in the gross. But the most accurate scientific system would still be only a method of description, and the actual facts would continue to rejoice in their own ways of being. The relevance and truth of science, like the relevance and truth of sense, are pragmatic, in that they mark the actual relations, march, and distribution of events, in the terms in which they enter our experience.