In this paper, I discuss the principle that bridges neural firing and perception, questioning some fundamental aspects of the neural correlates of conscious perception/cognition, which are central to the new trends in cognitive science. The assumption is that in order to understand perception, the state of neural firing in the brain is necessary and sufficient (the neuron doctrine in perception). The concept of response selectivity, currently the de facto central dogma in explaining the relation between neural firing and the mind, is found to be incompatible with the neuron doctrine. I put forward two new concepts, Mach’s principle in perception and the principle of interaction simultaneity. The latter is concerned with the origin of the subjective time. The approach outlined in this paper has elements common with the constructivist approch in cognitive science.