with an animated display of 2-dimensional shapes, they were inclined to ascribe intentions to the shapes. Further, Dennett (1987, p. 52) argues that, based on our fixed personal views of what all humans ought to believe, desire and do, we predict (or explain) the beliefs, desires and actions of others "by calculating in a normative system"; and, driven by the reasonable assumption that all humans are rational beings – who do have specific beliefs and desires and do act on the basis of those beliefs and desires in order to get what they want – these predictions/explanations are based on four simple rules: The agent's beliefs are those a rational individual ought to have (i.e., given their "perceptual capacities", "epistemic needs" and "biography"); In general, these beliefs "are both true and relevant to [their] life; The agent's desires are those a rational individual ought to have (i.e., given their "biological needs", and "the most practicable means of satisfying them") in order to further their "survival" and "procreation" needs; and The agent's behaviour will be composed of those acts a rational individual holding those beliefs (and having those desires) ought to perform. Dennett's three levels The core idea is that, when understanding, explaining, and/or predicting the behavior of an object, we can choose to view it at varying levels of abstraction. The more concrete the level, the more accurate in principle our predictions are; the more abstract, the greater the computational power we gain by zooming out and skipping over the irrelevant details. Dennett defines three levels of abstraction, attained by adopting one of three entirely different "stances", or intellectual strategies: the physical stance; the design stance; and the intentional stance: The most concrete is the physical stance, the domain of physics and chemistry, which makes predictions from knowledge of the physical constitution of the system and the physical laws that govern its operation; and thus, given a particular set of physical laws and initial conditions, and a particular configuration, a specific future state is predicted (this could also be called the "structure stance"). At this level, we are concerned with such things as mass, energy, velocity, and chemical composition. When we predict where a ball is going to land based on its current trajectory, we are taking the physical stance. Another example of this stance comes when we look at a strip made up of two types of metal bonded