Tag: Descartes

How Things Hang Together: the Lobster and the Octopus Redux

Posted on by Jochen Szangolies

by Jochen Szangolies

This is the fourth part of a series on dual-process psychology and its significance for our image of the world. Previous parts: 1) The Lobster and the Octopus, 2) The Dolphin and the Wasp, and 3) The Reindeer and the Ape

Figure 1: Postulated inner workings of the Canard Digérateur, or digesting duck, an automaton exhibited by Jacques de Vaucanson in 1739.

A (nowadays surely—or hopefully—outdated) view, associated with Descartes, represents animals as little more than physical automata (la bête machine), reacting to stimuli by means of mechanical responses. Devoid of soul or spirit, they are little more than threads of physical causation briefly made flesh.

It might perhaps be considered a sort of irony that the modern age has seen an attack on Descartes’ position from both ends: while coming to the gradual realization that animals just may have rich inner lives of their own, a position that sees human nature and experience to be entirely explicable within a mechanical paradigm, going back to La Mettrie’s 1747 extension of Descartes’ view to humans with L’Homme Machine, has likewise been gaining popularity.

This series, so far, can be seen as a sort of synkretistic take on the question: within us, there is both a rule-based, step-by-step, inferential process of conscious reasoning, as well as an automatic, fast, heuristic and unconscious process of immediate judgment. These are, in dual-process psychology, most often simply referred to as (in that order) ‘System 2’ and ‘System 1’.

In my more colorful (if perhaps not necessarily any more helpful) terminology, System 2 is the lobster: separated from the outside world by a hard shell, it is the Cartesian rational ego, the dualistic self, analyzing the world with its claws, taking it apart down to its smallest constituents.

System 1, on the other hand, is the octopus: more fluid, it takes the environment within itself, becomes part of it, is always ‘outside in the world’, never entirely separate from it, experiencing it by being within it, bearing its likeness. The octopus, then, is the nondual foundation upon which the lobster’s analytic capacities are ultimately founded: without it, the lobster would be fully isolated from the exterior within its shell, the Cartesian homunculus sitting in the darkness of our crania without so much as a window to look out of. Read more »

The Demon and the Reverend: How Doubt Unites Us

Posted on by Jochen Szangolies

by Jochen Szangolies

Thomas Bayes and Rational Belief

Bayes’ theorem in popular culture: the Big Bang Theory’s Sheldon Cooper trying to estimate his total lifespan

When we are presented with two alternatives, but are uncertain which to choose, a common way to break the deadlock is to throw a coin. That is, we leave the outcome open to chance: we trust that, if the coin is fair, it will not prefer either alternative—thereby itself mirroring our own indecision—yet yield a definite outcome.

This works, essentially, because we trust that a fair coin will show heads as often as it will show tails—more precisely, over sufficiently many trials, the frequency of heads (or tails) will approach 1/2. In this case, this is what’s meant by saying that the coin has a 50% probability of coming up heads.

But probabilities aren’t always that clear cut. For example, what does it mean to say that there’s a 50% chance of rain tomorrow? There is only one tomorrow, so we can’t really mean that over sufficiently many tomorrows, there will be an even ratio of rain/no rain. Moreover, sometimes we will hear—or indeed say—things like ‘I’m 90% certain that Neil Armstrong was the first man on the Moon’.

In such cases, it is more appropriate to think of the quoted probabilities as being something like a degree of belief, rather than related to some kind of ratio of occurrences. That is, probability in such a case quantifies belief in a given hypothesis—with 1 and 0 being the edge cases where we’re completely convinced that it is true or false, respectively.

Beliefs, however, unlike frequencies, are subject to change: the coin will come up heads half the time tomorrow just as well as today, while if I believe that Louis Armstrong was the first man on the moon, and learn that he was, in fact, a famous Jazz musician, I will change my beliefs accordingly (provided I act rationally).

The question of how one should adapt—update, in the most common parlance—one’s beliefs given new data is addressed in the most famous legacy of the Reverend Thomas Bayes, an 18th century Presbyterian minister. As a Nonconformist, dissent and doubt were perhaps baked into Bayes’ background; a student of logic as well as theology, he wrote defenses of both God’s benevolence and Isaac Newton’s formulation of calculus. His most lasting contribution, however, would be a theorem that gives a precisely quantifiable means of how evidence should influence our beliefs. Read more »