50. To gather up, then, the lines of contradiction which traverse Locke’s doctrine of real existence as it appears in his account of general and complex ideas:--The idea of substance is an abstract general idea, not given directly in sensation or reflection, but ‘invented by the understanding,’ as by consequence must be ideas of particular sorts of substances which presuppose the abstract idea. On the other hand, the ideas of sensation and reflection, from which the idea of substance is abstracted, and to which as _real_ it as an _invention_ is opposed, are ideas of ‘something,’ and are only real as representative of something. But this idea of something = the idea of substance. Therefore the idea of substance is the presupposition, and the condition of the reality, of the very ideas from which it is said to be derived. Again, if the general idea of substance is got by abstraction, it must be originally given in conjunction with the ideas of sensation or reflection from which it is afterwards abstracted, _i.e._ separated. But in such conjunction it constitutes the ideas of particular sorts of substances. Therefore these latter ideas, which yet we ‘come to have’ after the general idea of substance, form the prior experience from which this general idea is abstracted. Further, this original experience, from which abstraction starts, being of ‘sorts of substances,’ and these sorts being constituted by relations, it follows that relation is given in the original experience. But that which is so given is ‘real existence’ in opposition to the invention of the understanding. Therefore these relations, and the community which they constitute, really exist. On the other hand, mere individuals alone really exist, while relations between them are superinduced by the mind. Once more, the simple idea given in sensation or reflection, as it is made _for_ not _by_ us, has or results from real existence, whereas general and complex ideas are the workmanship of the mind. But this workmanship consists in the abstraction of ideas from each other, and from that to which they are related as qualities. It thus presupposes at once the general idea of ‘something’ or substance, and the complex idea of qualities of the something. Therefore it must be general and complex ideas that are real, as made for and not by us, and that afford the inventive understanding its material. Yet if so--if they are _given_--why make them over again by abstraction and recomplication? They cannot be overcome without violence to Locke’s fundamental principles.