The Evolution of Purposes - Presented by Prof Daniel Dennett

Robert Saint, the dean of the faculty of science at the University of Melbourne, opens the event by welcoming the audience and acknowledging the traditional owners of the land, the Wurundjeri people. He introduces Professor Daniel Dennett, a distinguished philosopher and professor at Tufts University, who has significantly influenced various fields such as human intentionality, consciousness, and evolutionary theory. Dennett's academic journey from Harvard to Oxford and his extensive publications are highlighted, setting the stage for his talk on the evolution of purposes.

Daniel Dennett begins his talk by discussing two types of 'why' questions: 'what for' and 'how come'. He explains that 'why' is ambiguous and can seek either a reason or a cause. Dennett outlines his presentation, which includes examining Darwin's contribution to understanding these questions, the unique human ability to represent reasons, and the intentional stance in both everyday and scientific perspectives. He emphasizes the importance of distinguishing between the two types of 'why' questions and the philosophical and scientific debate surrounding teleology, or the explanation of purpose in nature.

Dennett explores the concept of teleology, the explanation of phenomena in terms of their purpose or goal-directedness. He discusses the historical controversy surrounding final causes and the impact of Darwin's theory of natural selection on this debate. Dennett argues that Darwin's work provides a foundation for understanding teleology within a scientific framework, contrary to the belief that it negates the existence of purpose in the material world. He also addresses the idea of reductionism, suggesting that while some seek to reduce final causes to efficient and formal causes, others aim to understand the rational meaning behind teleological claims.

In this section, Dennett delves into the concept of normativity, particularly 'Pittsburgh normativity', which emphasizes the practice of asking, giving, and evaluating reasons. He contrasts this with 'consumer reports normativity', which focuses on the quality or value of an item. Dennett discusses the processes that correct deviations from norms, such as social correction and market forces. He illustrates the difference between the 'what for' sense of questions, which seek justification, and the 'how come' sense, which seeks a process narrative without justification.

Dennett provides examples to clarify the distinction between 'what for' and 'how come' questions. He uses anecdotes and examples from nature, such as the sorting of rocks on a beach, to illustrate how some phenomena can be interpreted as either type of question. He emphasizes that understanding this distinction is crucial for appreciating the different ways in which questions can be answered and the types of explanations sought.

Dennett discusses Charles Darwin's contribution to the understanding of evolution, particularly how natural selection can be seen as an algorithmic process. He describes natural selection as a set of sorting and generate-and-test algorithms that utilize randomness to create diversity. Dennett suggests that the gradualism inherent in Darwin's theory allows for the transition from 'how come' to 'what for' questions, as evolutionary processes lead to the development of features that are better at persisting and reproducing.

In this segment, Dennett considers the theoretical problem of the origin of life, suggesting that cycles in abiotic or prebiotic nature may have played a key role. He proposes that cyclical processes, or 'natural do-loops', could have gradually accumulated changes over time, increasing the probability of new events and the development of complexity. Dennett uses examples from nature to illustrate how cycles can lead to the formation of patterns and structures without the need for an intelligent designer.

Dennett argues that as natural selection operates over generations, it acts as an 'automatic reason finder', discovering and endorsing reasons that contribute to an organism's fitness. He emphasizes that this process is not driven by an intelligent agent but rather by the blind process of natural selection. Dennett suggests that the existence of well-adapted features in organisms introduces a normative standard of value, with natural selection optimizing these features over time.

Dennett concludes that Darwin's theory provides a way to unite 'what for' and 'how come' questions, starting with process narratives and leading to justifications for the existence of certain features. He asserts that we, as humans, are the only reason-representers in nature, capable of attributing purposes and reasons to phenomena. Dennett suggests that our ability to represent reasons is a product of evolution and that it allows us to understand the world in terms of reasons and purposes, which are real patterns in the world.

In the final part of his talk, Dennett discusses the intentional stance, the instinct to attribute beliefs and desires to agents. He argues that this stance is useful not only in everyday interactions but also in scientific inquiry. Dennett suggests that understanding the intentional stance in an evolutionary context allows us to appreciate the reasons and purposes that exist in nature, without anthropomorphizing non-human entities.

The session concludes with an audience member proposing an alternative interpretation of 'in the beginning was the word', suggesting that 'word' could be seen as an algorithm. Dennett appreciates the idea and reiterates the key points of his talk, emphasizing the role of blind mechanical processes in creating complexity and the emergence of intelligent design as a result of evolution. The audience is then thanked for their participation, and the session ends with applause and music.