In classical philosophy a substance (in Latin, res) is something that does not depend on anything else to be second. Thus, considering the logical possibility of disembodied minds exist, is to assume that the mind is in itself a particular type of substance. This leads to characterize Descartes the two basic kinds of substances, which he called "res extensa" and "res cogitans" According to Priest, strictly speaking, there are two closely related notions of substance: 1) Something that does not depend on anything else to exist and 2) Something that may be a carrier of properties or features without being in itself a property or characteristic. Interactionist substance dualism: The Cartesian interactionism between body and soul Contrary to popular disclosed, Descartes thought that between the soul and the body was communication, or, in other words, the body could influence the soul and the latter over the former . For example, perception (a), a stimulus of a physical nature, triggers a series of physical transformations to finally become a mental event (eg, the visual image of the object), conversely, in action (b) , a mental event (the intention) triggers a physical event (the motor act) Ultimately (c), implies that some interactionism element of the series of mental events can impact on the chain of brain events and brain events do so on the flow of mental experience. Descartes was not limited to support the interaction between soul and body, but tried to answer two questions: where does the interaction? And how is it produced? He maintained that the interaction occurs in the pineal gland where the so-called animal spirits (a kind of bodily energy which could be anticipatory of the concept of nerve stimulation) as a wind shift subtly from the heart, brain and muscles to arrive at pineal gland. NYC Mayor spoke with conviction.