The system is evolved in a series of theorems in severely demonstrative order out of the definitions and axioms which we have translated. To propositions 1--6 we have nothing to object; they will not, probably, convey any very clear ideas, but they are so far purely abstract, and seem to follow (as far as we can speak of "following," in such subjects), by fair reasoning. "Substance is prior in nature to its affections." "Substances with different attributes have nothing in common," and therefore "one cannot be the cause of the other." "Things really distinct are distinguished by difference either of attribute or mode (there being nothing else by which they can be distinguished), and therefore, because things modally distinguished do not qua substance differ from one another, there cannot be more than one substance of the same attribute; and therefore (let us remind our readers that we are among what Spinoza calls notiones simplicissimas), since there cannot be two substances of the same attribute and substances of different attributes cannot be the cause one of the other, it follows that no substances can be produced by another substance." The existence of substance, he then concludes, is involved in the nature of the thing itself. Substance exists. It does and must. We ask, why? and we are answered, because there is nothing capable of producing it, and therefore it is self-caused; i.e. by the first definition the essence of it implies existence as part of the idea. It is astonishing that Spinoza should not have seen that he assumes the fact that substance does exist in order to prove that it must. If it cannot be produced and exists, then, of course, it exists in virtue of its own nature. But supposing it does not exist, supposing it is all a delusion, the proof falls to pieces, unless we fall back on the facts of experience, on the obscure and unscientific certainty that the thing which we call the world, and the personalities which we call ourselves, are a real substantial something. Conscious of the infirmity of his demonstration, he winds round it and round it, adding proof to proof, but never escaping the same vicious circle: substance exists because it exists, and the ultimate experience of existence, so far from being of that clear kind which can be accepted as an axiom, is the most confused of all our sensations. What is existence? and what is that something which we say exists? Things--essences-- existences; these are but the vague names with which faculties, constructed only to deal with conditional phenomena, disguise their incapacity. The world in the Hindoo legend rested upon the back of the tortoise. It was a step between the world and nothingness, and served to cheat the imagination with ideas of a fictitious resting-place.