Summary
Highlights
The upcoming discussions will focus on Plato's dialogue, the Phaedo, which depicts Socrates's last day where he debates the immortality of the soul. Plato, a disciple of Socrates, wrote philosophical works in the form of dialogues, and in Phaedo, Socrates is presented as the mouthpiece for Plato's philosophical views. It's important to note the distinction between the historical Socrates's views and Plato's evolving philosophy, though for this course, Socrates's arguments within the dialogue will be treated as Plato's. The dynamic nature of dialogues means arguments can evolve, and positions may be modified throughout the discussion.
Previously, the argument was made that humans must have souls because machines cannot reason. However, this argument is challenged by the existence of chess-playing computers that demonstrate advanced reasoning abilities, including beliefs, desires, and strategic thinking. These programs do not simply calculate every possible move; they learn and adapt strategies much like human players. The best chess programs can now defeat grandmasters, indicating a sophisticated form of 'reasoning' that undermines the claim that reasoning is exclusive to non-physical beings.
A new argument for the soul suggests that while machines might reason, they cannot feel emotions. Science fiction examples like Marvin from 'The Hitchhiker's Guide to the Galaxy' or Hal from '2001: A Space Odyssey' depict robots exhibiting emotions like depression or fear. While these are fictional, the natural human inclination to ascribe emotions to these sophisticated machines implies that emotions might also be explicable in physical terms. If physical objects (like highly programmed computers) can exhibit behavior associated with emotions, then the need to posit a soul for emotions diminishes.
A critical distinction is drawn between the behavioral aspect of emotions (observable responses to danger, planning) and the experiential aspect (what it 'feels like' on the inside). While machines can replicate emotional behaviors, the qualitative, internal experience of feeling, often referred to as 'qualia,' remains a mystery for physicalists. Examples like seeing color or tasting flavors highlight this gap. The argument then is that no physical object can possess this qualitative aspect of experience, thus requiring a soul. The lecturer admits that consciousness and qualia are deep mysteries unsolved by current physicalist theories, comparing it to the difficulty of explaining life in material terms in the 14th century. However, not yet knowing how to explain it does not make it impossible, nor does simply positing a soul truly explain how consciousness arises.
Another argument for the soul stems from human creativity—the ability to compose music, write poetry, or invent new mathematical proofs. However, the lecturer questions this by pointing to chess programs like Deep Fritz, which make novel and creative moves previously unconsidered by humans. Similarly, mathematical theorem-proving programs and music composition programs demonstrate creativity by generating new and structured outputs. If machines can produce novel content, it challenges the idea that creativity necessitates a non-physical soul.
The final argument discussed is free will. It posits that while machines follow their programming mechanistically, humans possess free will, suggesting we are more than mere physical machines. The argument's structure is: (1) We have free will. (2) Nothing subject to determinism has free will. (3) All purely physical systems are subject to determinism. Therefore, we are not purely physical systems. This is a valid argument, meaning the conclusion logically follows from the premises. The critical question, which will be further explored, is whether all three premises are indeed true.