We now turn to the consideration of some• other in ferences deduced by the continental philosophers from Locke's principles, which are the very reverse of Ber keley's ideal scheme. If it is true that sensation is the inlet of all our knowledge, it seems to follow, as a na tural consequence, that there can be no ideas in the mind but such is have their orgin in material and sensible ob jects. At least this is the use which has been made of Locke's doctrine by the materialists on the continent. \Ve shall see by and by, that other continental writers give a very different interpretation to it.
The doctrine of the materialists, as deduced from Locke's principles, is thus stated by Diderot, in the 6th volume of his works. \Ve use the words of Mr. Stewart with very little alteration, which combine the light of a commentary with the fidelity of a translation. " Every idea must necessarily, when brought to its state of ulti mate decomposition, resolve itself into a sensible repre sentation or picture ; and since every thing in our un derstanding has been introduced there by the channel of sensation, whatever proceeds out of the understanding is either chimerical, or must be able, in returning by the same road, to re-attach itself to its sensible archetype. Hence an important rule in philosophy, that every ex pression which cannot find an external and a sensible ob ject to which it can attach itself, is destitute of signifi cation."
These are certainly most portentous consequences of Locke's doctrine, and such as neither he nor any of his sober admirers ever contemplated. They are made the foundation of the most avowed aid unqualified material ism ; and are employed to persuade us that we ought to reject from the book of human knowledge, every word which does not present a notion copied like a picture or image, from some archetype among the objects of ex ternal perception.
Such are the natural consequences of interpreting too literally the maxim of the schools, commonly supposed to have been prescribed by Aristotle, but which was framed in latter times, as a corollary deducible from his doctrine. The maxim, Nihi/ cat in intellectu, quod non fuit prius in sensu, when literally understood, must neces sarily, we should think, lead to materialism : for it im plies that the senses are the beginning and the end of all our knowledge ; a maxim which might easily be em ployed to cut up by the roots metaphysics, ethics, and religion. It is unfortunate that these sceptics, who have so eagerly perverted the doctrine, did not attend to a most judicious criticism made by Leibnitz, on the funda mental principle of Locke's system. It is in these words : Nem/se, nihil est in intellectu, quod non fuerit in sensu,