200. ‘Empirical psychology,’ however, claims to have a way of its own for explaining thought, distinct from that of the physiologist, but yet founded on observation, though it is admitted that the observation takes place under difficulties. Its method consists in a history of consciousness, as a series of events or successive states observed in the individual by himself. By tracing such a chain of _de facto_ sequence it undertakes to account for the elements common to all knowledge. Its first concern, then, must be, as we have previously put it, to ascertain what consciousness is to itself at its beginning. No one with Berkeley before him, and accepting Berkeley’s negative results, could answer this question in Locke’s simple way by making the primitive consciousness report itself as an effect of the operation of body. To do so is to transfer a later and highly complex form of consciousness, whose growth has to be traced, into the earlier and simple form from which the growth is supposed to begin. This, upon the supposition that the process of consciousness by which conceptions are formed is a series of psychical events--a supposition on which the whole method of empirical psychology rests--is in principle the same false procedure as that which we have imagined in the case of a geologist above. But the question is whether, by any procedure not open to this condemnation, the theory could seem to do what it professes to do--explain thought or ‘cognition by means of conceptions’ as something which happens in sequence upon previous psychical events. Does it not, however stated, carry with it an implication of the supposed later state in the earlier, and is it not solely in virtue of this implication that it seems to be able to trace the genesis of the later? No one has pursued it with stricter promises, or made a fairer show of being faithful to them, than Hume. He will begin with simple feeling, as first experienced by the individual--unqualified by complex conceptions, physical or metaphysical, of matter or of mind--and trace the process by which it generates the ‘ideas of philosophical relation.’ If it can be shown, as we believe it can be, that, even when thus pursued, its semblance of success is due to the fact that, by interpreting the earliest consciousness in terms of the latest, it puts the latter in place of the former, some suspicion may perhaps be created that a natural history of self-consciousness, and of the conceptions by which it makes the world its own, is impossible, since such a history must be of events, and self-consciousness is not reducible to a series of events; being already at its beginning formally, or potentially, or implicitly all that it becomes actually or explicitly in developed knowledge. It only seems to do so by assuming the ‘fiction’ it has to account for; by assuming that impression represents a real world.