 Hering argues that the ability to experience objects as a single, spatially ordered image is a disposition inborn in human children, and not acquired. While children may not be born with the ability to resolve two images into one, Hering claims that the ability develops when a child grows to maturity, and is not learned. Hering argues that depth perception and stereoscopic vision are inherent physical abilities, like running or even breathing, that can be honed but are not learned wholesale from experience. In fact, to Hering, the adjustments the brain and eyes make to different inputs are automatic and involuntary, like a heartbeat. Helmholtz contends that depth perception and stereoscopic vision require reciprocal adjustment to objects and thus are skills that must be learned through experience, like shaving in front of a mirror (an example he takes from Müller, see Otis 2007, 129). When shaving in front of a mirror, one must learn to distinguish right from left in the mirror, and to turn the right or left side of one’s face to the mirror correctly, even though the apparent motion in the mirror is the opposite of the felt motion in one’s body. Helmholtz argues that the ability to shave in front of a mirror cannot be innate, because it requires learned adjustments to the properties of one’s environment, that reflections in a mirror are inverted, for instance. 