<p style='text-align: justify;'>The <i>Philosophia pauperum</i>, frequently attributed to Albertus Magnus, is now believed to have been compiled by another thirteenth-century Dominican, Albertus of Orlamuende. The <i>Philosophia pauperum</i> was a popular compilation of Aristotle's <i>Physics </i>and <i>On the Soul</i>, printed eight times before 1501. This woodcut shows a profile of a hairless head of a man; the clothing resembling a cowl suggests that he might be a monk. Around the head at the top are labels for the three ventricles (<i>ventriculus</i>), though the third one at the back of the head is only partly visible in this image because of the tight binding of the book. The first circle contains common sense (<i>sensus communis</i>) and imagination (<i>imaginatio</i>). The second circle contains the estimative (<i>extimatio</i>) and imaginative senses (<i>imaginativa</i>), The third circle contains memory (<i>memoria</i>) and the power that moves the limbs (<i>membrorum motiva</i>). In <i>On the Soul</i>, Aristotle classified three stages of the soul: the nutritive, the sensitive and the rational. These functions were distinct in the sense that one could find beings with only one or two of them. Plants had the nutritive function alone, animals both the nutritive and sensitive functions, and humans all three. The nutritive and sensitive souls required organs, while the rational soul did not. Under the sensitive soul, in addition to the five exterior senses of seeing, hearing, smell, taste and touch, Aristotle had rather vaguely posited common sense, imagination and memory as functions operating after initial sense perception by the five external senses. These post-exterior senses were developed into 'internal' senses in the Arabic tradition, and had a long history of reception in the Latin West, with varying views concerning their numbers and locations. The <i>Philosophia pauperum </i>explicitly follows Avicenna (980-1037): the '<i>sensus communis</i>' collates and compares the perceptions received from the five external senses, and '<i>imaginatio</i>' retains those perceptions; the 'imaginative' sense, which is also called the 'cogitative' or 'formative' sense, has the power to combine these perceptions to create, for example, 'a castle in the air', while the 'estimative' sense reminds animals of their natural enemies and enables animals to build nests and webs; 'memory' retains all these perceptions and notions. As functions of the sensitive soul, the internal senses were allotted organs ' here the '<i>sensus communis</i>' and the '<i>imaginatio</i>' are placed in the front ventricle of the brain, the 'imaginative' and 'estimative' in the middle ventricle of the brain, and memory in the back ventricle of the brain. The depiction of the internal senses, often combined with the five exterior senses, is one of the few stock illustrations that can be found in pre-modern natural philosophy textbooks.</p>
