Tactition is the sense of pressure perception. This definition is the one that differs the most from the Aristotelian model, as it specifically excludes the perception of pain and temperature (classified separately). Even within the limited field of "pressure" there is still disagreement as to how many distinct senses there actually are. In the skin, for example, there are different receptors responsible for the detection of light against heavy pressure, as well as brief against sustained pressure. Adding to the complexity is the fact that there are also distinct receptors that detect pressure in the visceral organs, such as that caused by a full stomach, and endocrinal receptors that cause the feeling of "tension", such as that associated with anxiety or excessive caffeine consumption.
See also Touch.