The figures Knowles suggests for andragogy (teaching adult learners) are the art and science of learning. In his 1980 edition of his book, Knowles modifies his first position by saying pedagogy and androgoy are opposite ends of a spectrum of teaching/learning techniques that may be applicable for a given student. The utility of the art-science continuum to the learner is that they can select from the elements on that spectrum to meets their needs for learning and application to real-life needs.
The term "andragogy" was originally coined in the nineteenth century to refer to adult education. The term "pedagogy" is Greek, meaning, literally "the leading of children", from the Greek word pais (stem, "paid-") meaning "child" and "ago" (lead). The term andragogy takes as its root ἀνήρ (genitive ἀνδρός), which means "man", and thus refers to educating adult men. The particular coinage reveals either a strongly patriarchal bias or ignorance of the Greek language, as the term ἀνήρ is specifically used to distinguish men from women, as opposed to the term άνθρωπος, used to refer to human beings without respect to gender.
The American educator Malcolm Shepherd Knowles (1913 – 1997) popularized this in English as a generic term for adult learning (either unaware of the significance of the Greek roots or not particularly concerned with educating women).
The main elements of Knowles' theory have to do with the differences in motivation and learning styles between adult and younger learners. He argues that adults are more likely to be internally motivated and self-directed in their learning and respond best when made equal partners in the learning experience. He also argues that adult learners are most interested in directing their own learning in directions that are specifically relevant to their own lives and careers.