If we realise these characteristics of paramnesia we can scarcely fail to conclude that we are concerned here with illusions which, while they fall within the sphere of memory, are largely conditioned by the whole psychic condition. As in dreams, it is inattention, failure of apperception, defective association of the mental contents, which make the paramnesia possible. Paramnesia is, as Fouillée has said, a kind of diplopia or seeing double in the mental field. 'I have the impression,' says one of the writers on this subject who himself experiences the sensation, 'that the present reality has a _double_.' Actual double vision is due to the failure of that muscular co-ordination which, as Ribot and others have insisted, is of the very essence of attention. This wider psychic basis on which paramnesia rests has of late been recognised by several psychologists. Thus Léon-Kindberg states that in paramnesia there is an absence of mental attention, of the effort of synthesis necessary to grasp an actual occurrence, which is, therefore, perceived with the same facility as a memory not requiring synthesis, with the resulting illusion that it is a memory.[236] Ballet, again, regards paramnesia as a transitory or permanent psychasthenic state, due to dissociation.[237] Dugas, also, who has repeatedly returned to this subject during many years, in his latest contributions attaches primary importance to this broader factor of paramnesia. In analysing memory, he says, there is an element which, though often overlooked, is capital: the recognition of a state of consciousness not merely as passed, but as bound up with our own personal past; when that synthetic function ceases to be accomplished, or is only accomplished defectively, then memory is lacking or perverted. Nervous weakness, he proceeds, produces failure of attention, the inhibitory power of attention being no longer exerted, and the psychic elements fall back to anarchy. Now many psychic states, such as sensations, recollections, and images, differ from each other less by their substance than by the way in which the mind takes hold of and apprehends them. The mind seizes a sensation with a stronger grasp than a recollection, and a recollection with a stronger grasp than an image. When attention is relaxed the line of demarcation between these psychic states tends to be effaced; the sensation becomes vague and floating like the recollection and the image, while the recollection and the image, on the contrary, become objective and acquire something of the brilliance and relief of the sensation. The very same cause--enfeeblement of attention--thus produces opposite effects, on the one side raising the tone, on the other lowering it, so that states of mind which are ordinarily distinct tend to be approximated and confused, as we may observe in the hypnagogic condition.[238]