Gregorić additionally argues that Aristotle can be interpreted as using the verbs and to distinguish two types of thinking or awareness, the first being found in animals and the second unique to humans and involving reason. Therefore, in Aristotle (and the medieval Aristotelians) the universals used to identify and categorize things are divided into two. In medieval terminology these are the used for perception and imagination in animals, and the or apprehendable forms used in the human intellect or . Aristotle also occasionally called the (or one version of it) the (, ). (According to Gregorić, this is specifically in contexts where it refers to the higher order common sense that includes imagination.) Later philosophers developing this line of thought, such as Themistius, Galen, and Al-Farabi, called it the of the senses or sense, apparently a metaphor developed from a section of Plato's "Timaeus" (70b). Augustine and some of the Arab writers, also called it the "inner sense". The concept of the inner senses, plural, was further developed in the Middle Ages. Under the influence of the great Persian philosophers Al-Farabi and Avicenna, several inner senses came to be listed. "Thomas Aquinas and John of Jandun recognized four internal senses: the common sense, imagination, , and memory. Avicenna, followed by Robert Grosseteste, Albert the Great, and Roger Bacon, argued for five internal senses: the common sense, imagination, fantasy, , and memory." By the time of Descartes and Hobbes, in the 1600s, the inner senses had been standardized to "five wits", which complemented the more well-known five "external" senses. Under this medieval scheme the common sense was understood to be seated not in the heart, as Aristotle had thought, but in the anterior Galenic ventricle of the brain. The great anatomist Andreas Vesalius however found no connections between the anterior ventricle and the sensory nerves, leading to speculation about other parts of the brain into the 1600s.  "" is the Latin translation of the Greek , which came to be recovered by Medieval scholastics when discussing Aristotelian theories of perception. However, in earlier Latin during the Roman empire the term had taken a distinct ethical detour, developing new shades of meaning. These especially Roman meanings were apparently influenced by several Stoic Greek terms with the word (); not only , but also such terms as (), (), and , all of which involve —something, at least in Aristotle, that would not be present in "lower" animals.