  A different kind of solution is offered by Mark Johnston (1992) and E. J. Lowe (1982, 1995). Both of them suggest that the key to solving the Problem is to distinguish cloud-constituters from clouds. They say it is a category mistake to identify clouds with any fusion of water droplets, because they have different identity conditions. The cloud could survive the transformation of half its droplets into puddles on the footpath (or whatever kind of land it happens to be raining over), it would just be a smaller cloud, the fusion could not. As Johnston says, “Hence Unger's insistent and ironic question ‘But which of o1, o2, o3, … is our paradigm cloud c?’ has as its proper answer ‘None’.” (1992: 100, numbering slightly altered).