The world and everything that it consists of is composed of physical matter and therefore everything can be explained by science and nature. In fact, much of the mysteries since the time of Plato and other dualists that struggle with the relationship between mind and body have been solved by advancements in psychology and research. Living in the 21st century, we now understand that our psychological wants, drives, and emotions are controlled by various parts of the brain with plenty of hormone and neuron messengers. Neuroscience has taught us that our emotions are mostly dictated by the amygdala and hypothalamus in our brains, functioning to classify and store incoming sensory input from our experiences. It is also responsible for our natural drives for sex, appetite, and hunger, which undoubtedly dictate many of our choices during our daily life. Our frontal lobe is the main control house for our body and responsible for what ancient philosophers would call the "soul" except modern science would not say that this "soul" is immortal. The frontal lobe is responsible for functions of upper level thinking such as reasoning, problem solving, empathy, altruism, judgement, and impulse control. It is the last part of our brains to develop which explains why we are more capable of being independent and making responsible decisions as adults as compared to ourselves as children. The soul in a constant state of change- as old dualists would describe- can be explained by the developing brain and how it is changed due to different experiences contributing different sensory input. In short, the immortal soul and mortal physical body have been proven to be really one unified unit since whatever happens to the body will effect the mind and vice-versa. The human spirit can be explained completely by neuroscience and everything is just another part of our natural, material world.
