Since the seventeenth century, mind-body dualism has undergone an evolution, both in its metaphysics and its supporting arguments. In particular, debates in seventeenth- and eighteenth-century England prepared the way for the fall of substance dualism—the view that the human mind is an immaterial substance capable of independent existence—and the rise of a much less radical property dualism. The evolution from the faltering plausibility of substance dualism to the growing appeal of property dualism depended on at least two factors. On the one hand, there was an increasing recognition of the causal and ontological interdependence of mind and body. Important here was a growing appreciation of the dependence of thought and perception on complex activities in the brain. On the other hand, there was a reconceptualization of the nature of matter; no longer inert and passive, matter came to be viewed as active in its own right. The old arguments lost much of their force, opening the door to a new sort of argument. Rather than appealing to the supposed immaterial nature of mental substance and volition, arguments for dualism began to appeal to the subjective nature of conscious experience—and its inexplicable emergence from the brain—as proof of the ontological distinctiveness of conscious properties. Consequently, the nineteenth and twentieth centuries saw the ascent of a more plausible, but still very problematic, property dualism, a position that to this day enjoys significant support.