Nutritive, Sensitive and Rational capacities of soul
Aristotle held that the soul was that which enabled the materials constituting an individual plant-based, or an animate, form of potential life
to engage in the necessary activities to those materials collectively functioning as an actual form of life.
Aristotle's three parts soul concept proposed that a nutritive soul was common to both plant-based and animate forms of life enabling the
intake and absorption of nutrients, growth towards maturity, the generation of progeny and the engagement in behaviors promotive
of the survival of the growing, maturing, breeding life-form and its progeny.
Aristotle's three parts soul concept further proposed that a sensitive soul could exist in animate forms of life allowing perceptions
of the world. Whilst most animate forms of life were held to be capable of experiencing appetites and desires and being sensitive to
pleasures and pain.
Aristotle made a distinction within animate forms of life. He saw what he termed passive intellect
as a rational soul capacity for the taking in and remembering of information and what he termed active intellect as a rational soul
capacity for actually holding beliefs or other forms of conviction, thinking and philosophising.
Full rational soul capability was something Aristotle viewed as being confined to Human Beings. The holding of beliefs and convictions, according
to Aristotle, depended on capacities for rationality which he deemed to be only present in Human souls and absent from animal souls.
Key sources supportive of Tripartite Theory of Soul