But although the extreme doctrine of the Idealist metaphysicians, that objects are nothing but our sensations and the laws which connect them, has not been generally adopted by subsequent thinkers; the point of most real importance is one on which those metaphysicians are now very generally considered to have made out their case: viz., that _all we know_ of objects is the sensations which they give us, and the order of the occurrence of those sensations. Kant himself, on this point, is as explicit as Berkeley or Locke. However firmly convinced that there exists an universe of “Things in themselves,” totally distinct from the universe of phenomena, or of things as they appear to our senses; and even when bringing into use a technical expression (_Noumenon_) to denote what the thing is in itself, as contrasted with the _representation_ of it in our minds; he allows that this representation (the matter of which, he says, consists of our sensations, though the form is given by the laws of the mind itself) is all we know of the object: and that the real nature of the Thing is, and by the constitution of our faculties ever must remain, at least in the present state of existence, an impenetrable mystery to us.(13) There is not the slightest reason for believing that what we call the sensible qualities of the object are a type of anything inherent in itself, or bear any affinity to its own nature. A cause does not, as such, resemble its effects; an east wind is not like the feeling of cold, nor heat like the steam of boiling water: why then should matter resemble our sensations? why should the inmost nature of fire or water resemble the impressions made by these objects upon our senses?(14) And if not on the principle of resemblance, on what other principle can the manner in which objects affect us through our senses afford us any insight into the inherent nature of those objects? It may therefore safely be laid down as a truth both obvious in itself, and admitted by all whom it is at present necessary to take into consideration, that, of the outward world, we know and can know absolutely nothing, except the sensations which we experience from it. Those, however, who still look upon Ontology as a possible science, and think, not only that bodies have an essential constitution of their own, lying deeper than our perceptions, but that this essence or nature is accessible to human investigation, cannot expect to find their refutation here. The question depends on the nature and laws of Intuitive Knowledge, and is not within the province of logic.