  (b) The ‘consciousness’ account: The view that consciousness is the substance. Account (a) allowed the immaterial substance to have a nature over and above the kinds of state we would regard as mental. The consciousness account does not. This is Descartes’ view. The most obvious objection to this theory is that it does not allow the subject to exist when unconscious. This forces one to take one of four possible theories. One could claim (i) that we are conscious when we do not seem to be (which was Descartes’ view): or (ii) that we exist intermittently, though are still the same thing (which is Swinburne’s theory, (1997), 179): or (iii) that each of us consists of a series of substances, changed at any break in consciousness, which pushes one towards a constructivist account of identity through time and so towards the spirit of the bundle theory: or (iv) even more speculatively, that the self stands in such a relation to the normal time series that its own continued existence is not brought into question by its failure to be present in time at those moments when it is not conscious within that series (Robinson, forthcoming).