 Perception is a good example. The perceptual system transforms proximal sensory stimulations (e.g., retinal stimulations) into perceptual estimates of environmental conditions (e.g., estimates of shapes, sizes, colors, locations, etc.). Helmholtz (1867 [1925]) proposed that the transition from proximal sensory input to perceptual estimates features an unconscious inference, similar in key respects to high-level conscious inference yet inaccessible to consciousness. Helmholtz’s proposal is foundational to contemporary perceptual psychology, which constructs detailed mathematical models of unconscious perceptual inference (Knill &amp; Richards 1996; Rescorla 2015). Fodor (1975: 44–55) argues that this scientific research program presupposes mental representations. The representations participate in unconscious inferences or inference-like transitions executed by the perceptual  system.[5]