Maslow's hierarchy of needs includes: physiological, safety, love/belonging, esteem, self actualisation. All four lower levels must be met before the individual can reach self-actualisation and fulfill their potential.
Rogers' client centred therapy focuses on empathy, positive regard and genuineness. The aim is to reduce incongruence. The therapy is non-directive which allows for a patient to discover solutions that are unique to them.
The humanistic approach assumes that people have free will, a person can only be understood as a whole, and generalisations cannot be made as the individual is unique.
Rogers argued that for personal growth to be achieved, an individual's concept of self must be congruent with their ideal self. If there is too big of a gap then a person will experience incongruence and a lack of self-worth.
Rogers believed incongruence is caused by having 'conditions of worth' imposed onto us from a young age by our parents. This can be reduced through developing a more realistic vision of our ideal self and recieving unconditional positive regard.
The humanistic approach lacks scientific merit. It believes in free will over determinism, i.e. nothing has a cause so nothing can be explained scientifically. The belief in holism also means no variables can be tested individually so cause and effect can never be shown fully.
Because the humanistic approach is idiographic, its real-life applications are very limited in terms of making predictions and generating treatments. It also has limitations cross culturally as it focuses hugely on the individual. This would not apply in collectivist cultures such as China. Also some religious people do not believe in free will.