Ever since its inception in the 1950s, Applied Behavior Analysis (ABA) has been the occasional target for criticism by the developmental disability community, psychiatrists, psychologists, and others that view ABA as a mechanistic and unnatural intervention. Sometimes, the general public has outrightly rejected ABA as an unethical and traumatizing intervention. These critiques stem from several misconceptions but also, to be fair, from an accurate portrayal of some early implementations of ABA that in fact, by today’s standards, would be considered at best unacceptable. In addition, what is often offered as “ABA” is not what properly trained behavior analysts would consider high-quality, bona fide ABA. In this chapter, first, the origins of ABA will be reviewed, with experimental behavior analysis as its foundation, followed by a discussion of early challenges that may have led to approaches in ABA that today are rightfully considered unacceptable. Next, the discrete-trial training (DTT) approach (a common target for criticism and often seen, incorrectly, as representing the entire field of ABA) will be contrasted with the Natural-Learning Paradigm (NLP), even though the DTT approach may still be the intervention of choice for some individuals. Finally, a person’s Right to Effective Treatment along with ethical considerations will be discussed, as well as NLP in relation to neurodiversity and ABA’s appreciation of unequivocal respect for individual dignity and self-determination.