Final answer:
Aristotle's concept of Akrasia explains why someone might act against what they know is right, due to a weakness of will or conflicting desires, despite their rational understanding aiming towards eudaimonia.
Step-by-step explanation:
The psychological phenomenon that Aristotle referred to, describes a situation where someone acts against what they suppose is right, is known as Akrasia. This concept is often aligned with the idea of 'weakness of will' or acting against one's better judgement.
In contrast, cognitive dissonance refers to the psychological discomfort from inconsistent beliefs and behaviors, while cognitive bias encompasses various subconscious errors in thinking. Ethical relativism, on the other hand, posits that moral standards are determined by cultural context and are not absolute or universal.
Aristotle believed that individuals have the capacity for rational thought which guides them towards actions conducive to their ultimate good, which he identified as eudaimonia (flourishing or well-being). However, due to poor habits or lack of moral virtue, an individual may experience Akrasia, where they know the correct action but fail to perform it due to conflicting desires or weaknesses.