might be said to be ignorant of a language we had never learned. But the other ignorance (not, properly speaking, ignorance at all) is incident to _all_ intelligence by its very nature, and is no defect or imperfection. The law of ignorance hence is that 'we can be ignorant only of what can be known,' or 'the knowable is alone the ignorable.' The bearing of this important point is seen at once when we turn back to the theory of knowing. Knowledge is something of which the subject cannot shake himself free; 'I' must always, in whatever I apprehend, apprehend 'me.' We don't apprehend 'things,' that is, but what is apprehended is 'me-apprehending-things.' Things-plus-me is the only knowable, and consequently the only 'ignorable.' This brings us a great way towards the Absolute Idealism associated mainly with the name of Hegel--towards the Knowledge or 'Experience' (a word which Ferrier afterwards himself makes use of) which shall cease to be a 'theory,' being recognised as comprehending within itself all Reality--as recognising no distinction between object and subject, excepting when they are regarded as two poles both equally essential, and separated only when looked at in abstraction. If Ferrier's 'theory of knowledge' did not proceed so far, he at least made the discovery that the subjective idealism of Kant was as unsatisfactory as the relativity of Hamilton, and as certainly tending to agnosticism. Kant's 'thing-in-itself' is not that of which we are ignorant, or a hidden reality which can be known by faith. It is that which cannot possibly be known--and, in other words, a contradiction or nonsense. Now, Ferrier says, we arrive at the true Idealism--the triumph of philosophy. If it is said to reduce all things to the phenomena of consciousness, it does the same to every _nothing_. What falls out of consciousness becomes incogitable; it lapses, not into nothing, but into what is contradictory. The material universe _per se_, and all its qualities _per se_, are not only absolutely unknowable, but absolutely unthinkable. We do indeed know substance, but only as object plus subject--as matter _mecum_ or in cognition as thought together with the self.