After George Berkeley, the philosophy of David Hume (1711-1776) gave rise to scepticism which swept away the existence of mind together with that of matter. "We know the mind" said Hume, "only as we know matter by perception, though it may be in this case internal." Never do we perceive any such entity as the mind, we perceive merely separate ideas. The mind is not a substance but an organ that has ideas, it is only an abstract name for series of ideas; the perceptions, memories and feelings are the mind; there is no observable "soul" behind the processes of thought". The result appeared to be that Hume had as effectually destroyed mind as Berkeley had destroyed matter. Nothing was left; and philosophy found itself in the midst of ruins of its own making. No wonder that a wit advised the abandonment of the controversy, saying, "No matter, never mind".[1]
Comparing Hume and Berkeley, while the former's conclusions are purely skeptical, the latter can be called a subjectivist at least in respect to the physical world.