Physicist Carlo Rovelli recently proclaimed that consciousness is just another physical thing, while materialist philosophers argue that consciousness is simply one brain state observing another. What such views miss, argues Manfred Frank, a leading figure in contemporary German philosophy, is that consciousness comes with a built-in awareness of itself—an awareness that exists prior to any introspection or observation. Consciousness does not observe itself in the way we observe objects; rather, it dissolves the distinction between observer and observed altogether. This is why consciousness cannot be simply another object in the world, but instead exists in an entirely different dimension.

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If we had no consciousness our lives would be devoid of meaning. We have been immersed in this medium since before we were born and remain in it even in our dreams. And we do so without any effort on our part. Apart from when it is interrupted by deep sleep or we are unconscious after fainting or during anaesthesia, we remain in this state or are enveloped in it throughout our entire lives. Nothing is more familiar to us than consciousness; it is so familiar that we rarely notice it or attend to it.

Methods to acquire and process synaptic-resolution electron-microscopy datasets have progressed very rapidly, allowing production and annotation of larger, more complete connectomes. More accurate neuronal matching techniques are enriching cell type data with gene expression, neuron activity, behaviour and developmental information, providing ways to test hypotheses of circuit function. In a variety of behaviours such as learned and innate olfaction, navigation and sexual behaviour, connectomics has already revealed interconnected modules with a hierarchical structure, recurrence and integration of sensory streams.