Haptic communication many terms such as positive, playful, control, ritualistic, task-related or unintentional. It can be both sexual (kissing is one example that some perceived as sexual), and platonic (such as hugging or a Handshake). Touch is the earliest sense to develop in the fetus. The development of an infant's haptic senses and how it relates to the development of the other senses such as vision has been the target of much research. Human babies have been observed to have enormous difficulty surviving if they do not possess a sense of touch, even if they retain sight and hearing. Infants who can
Analogy of the sun region in which truth and real being brightly shine, it understands and knows it and appears to have reason; but when it has nothing to rest on but that which is mingled with darkness—that which becomes and perishes, it opines, it grows dim-sighted, changing opinions up and down, and is like something without reason. ('The Republic, VI: 508d; trans. W. H. D. Rouse) The allusion to "...that which becomes and perishes..." relates to all of that which is perceived by the bodily senses. The bodily senses make it clear that all visible things are subject to change, which Socrates categorizes