The Emergence of Probability (1975) by Ian Hacking

The Emergence of Probability (1975) by Ian Hacking

I’ve always been awful at probability in math, but enthralled by statistics - analytics and stuff. So as much as the technical aspects of this book left me confused and frustrated, Hacking’s deep-dive into the history and philosophy behind probability’s inception was fascinating enough to keep me going.

Hacking acknowledges several isolated incidents of probability as a defined concept throughout history, but marks the publication of Port Royal’s “Logic” at the end of the 1600s as the point where probability truly embedded itself into the public consciousness as a defined, academic field.

Early on, “probability” held a much different connotation than it does today. To be “probable” actually signified approval by authority rather than statistical likelihood. But as an effort to decipher the “universal language” of nature emerged in the mid-1600s, there was finally a distinction between probability based on “internal evidence” (concrete, intrinsic signs) and “external evidence” (testimony).

Probability entered the realm of mathematics, unfortunately yet understandably, through gambling. And it entered the realm of logical processing, surprisingly enough, by the philosophical question of God’s existence. Meanwhile, a mixture of these mathematical and logical aspects of probability came together in an attempt to quantify judgment in law. This was thanks to Leibnitz, a “founding father” of modern probability, who attempted to weigh conditional rights (in a legal sense) with fractions.

Historically, academic documentation was written in Latin, but probability posed an interesting issue to that precedent since many of its concepts could only be properly expressed in “layman’s terms”. This led to a lot of mathematical dispute between scholars who derived different solutions to the same statistical problems merely because they interpreted the wording of the question differently.

Some of the more philosophical dissections of probability created redundant, circular reasoning. For example, the distinction between “aleatory” probability (the mathematical chances of an occurrence) and “epistemic” probability (our degree of belief based on situational knowledge), leads to cases where we have (epistemic) probabilities of (aleatory) probabilities.

Hacking even dives into some early theological implications of probability, like Bernoulli’s “degrees of certainty”, where absolute certainty is restricted to divine predetermination, and the 1700s British Royal Society’s insistence on the divine “balance of nature” to explain statistical laws that seem to diverge from equal probability (like how male births slightly outnumber female births - but level out in the general population due to higher male mortality rates).

But arguably the most philosophical query presented by probability is Hume’s “problem of induction”, which questions whether we can rightfully judge future events based on past experiences - to the extent that we might even question whether or not we can actually know the next sandwich we eat will nourish us just because we’ve never experienced otherwise. Ultimately, though - Hume recognizes that cause-and-effect reasoning based on the recognition of ‘habitual connections’ is sound.

There are plenty of other interesting takeaways in this book, like the differences between “probability” and “possibility”, but I just wish Hacking’s writing wasn’t too obtuse to understand properly. There were times where I felt like I was reading a textbook, and that Hacking expected a prerequisite knowledge of high-level math and European history from his readers - and I fell very short of this expectation. But at least I got some interesting insights into early probability here, and I was definitely fascinated by everything I could actually grasp.