Final answer:
Carl Rogers's consistent theme in his writings is self-actualization. He believed in the innate potential of individuals to strive towards becoming their best selves.
Step-by-step explanation:
Carl Rogers's consistent theme in his writings is self-actualization. Rogers believed that individuals have the innate potential to strive towards becoming the best version of themselves. He emphasized free will and self-determination, with each individual aspiring to achieve congruence between their real self and ideal self, leading to a greater sense of self-worth and a healthy, productive life.