multiplicity of sensations
Mary Shelley posits the Lockean notion
that at first one's natural condition is that of synaesthesia, an
indiscriminate intermingling of sense experience: only when the intellect
begins consciously to analyze sensory data are they broken down according
to the five diverse senses. The physiological basic for this development
had been posited in the mid-eighteenth century by the French materialist
philosopher Condillac, in his Traité des sensations.
Deliberate synaesthesia is an artistic ploy often to be found among the
English Romantic poets, in none more than Percy Bysshe Shelley: see, for
instance, his poem of 1818,
"Lines Written among the Euganean Hills," esp. line 285 ff.