Steven Pinker - Rationality (Allan Lane, 2021) ***½

In "Enlightenment Now", Steven Pinker advocates for better use of rationality and scientific thinking in our everyday world, which leads to progress for all thanks to better technology, better decision-making and more democracy and humanism. 

In "Rationality" he gives a course in rationality, with all its different components: logic and critical thinking, probability and randomness, Bayesian reasoning, rational choice and expected utility, signal detection and statistical decision-theory, game theory, correlation and causation. This interesting overview will of course not bring much new to scientists or other highly educated readers who are familiar with the basics of our rationality. 

To me, the content of this book, together with some deeper insights in cognitive sciences should be compulsory in any school curriculum. 

"We should be creative in changing the rules in other arenas so that disinterested truth is given an edge over 'myside' bias. In opinion jour­nalism, pundits could be judged by the accuracy of their forecasts rather than their ability to sow fear and loathing or to fire up a fac­tion. In policy, medicine, policing, and other specialties, evidence­ based evaluation should be a mainstream, not a niche, practice. And in governance, elections, which can bring out the worst in reasoning, could be supplemented with deliberative democracy, such as panels of citizens tasked with recommending a policy. This mechanism puts to use the discovery that in groups of cooperative but intellectually diverse reasoners, the truth usually wins. 

Human reasoning has its fallacies, biases, and indulgence in my­thology. But the ultimate explanation for the paradox of how our species could be both so rational and so irrational is not some bug in our cognitive software. It lies in the duality of self and other: our powers of reason are guided by our motives and limited by our points of view. (...)  So, too, is impartiality the core of rationality: a reconciliation of our biased and incomplete notions into an understanding of reality that transcends any one of us. Rationality, then, is not just a cognitive virtue but a moral one".

One of the biggest unresolved issues in the use of rationality, and a topic that has rarely been investigated, also not here by Pinker, is the fact that people use all the methods of rationality in concrete and non-complex tasks. It is only when a certain level of abstraction and complexity has been reached, that our rational tools no longer seem to work and that other factors start interfering, such as emotions, beliefs, ideological values, self-interest. We have the tools, we just don't use them all the time. So the question remains how we can extend these tools to all our thinking and decision-making. 

In any case, the book is a worthwhile overview of all the aspects of rationality, but for most highly educated readers, it will come as a confirmation of existing knowledge rather than as an eye-opener.