The Existential triad 

How do we infer life? When we perceive a body in motion independent of external impulses and together when we witness its organic growth over time, we then acknowledge the miracle of life in the form of an idea. The body, the idea of awareness i.e. the consciousness and the autonomous energy as the cause of motion often referred to as the soul - confirms existence. Thus, the body, consciousness and soul constitute the existential triad, the absence of any component of this triad is enough to cast reasonable doubt over existence. 

Wherever we find life, we observe the existential triad - in animals as well as plants. Most of us won't wonder or bother about body and soul, but in matters of consciousness, we may differ. But botanical research has confirmed the elements of consciousness in plants too. They do respond to light and sound, which would have been impossible without consciousness. What varies across living beings is the degree of consciousness. Humans are at the top of the consciousness ladder if we dare exclude any extra-terrestrial existence. It's the layer where consciousness evolves to self-consciousness. Mind is nothing but the by-product of self-consciousness - the phenomenon that begins with ‘I’.