I have just finished Leo Tolstoy’s War and Peace, and along the way marked a couple of passages.
The first two fit with the story that much behavioural science is formalisation of common sense. First, hindsight bias:
In historical works on the year 1812 French writers are very fond of saying that Napoleon felt the danger of extending his line, that he sought a battle and that his marshals advised him to stop at Smolensk, and of making similar statements to show that the danger of the campaign was even then understood. Russian authors are still fonder of telling us that from the commencement of the campaign a Scythian war plan was adopted to lure Napoleon into the depths of Russia, and this plan some of them attribute to Pfuel, others to a certain Frenchman, others to Toll, and others again to Alexander himself—pointing to notes, projects, and letters which contain hints of such a line of action. But all these hints at what happened, both from the French side and the Russian, are advanced only because they fit in with the event. Had that event not occurred these hints would have been forgotten, as we have forgotten the thousands and millions of hints and expectations to the contrary which were current then but have now been forgotten because the event falsified them. There are always so many conjectures as to the issue of any event that however it may end there will always be people to say: "I said then that it would be so," quite forgetting that amid their innumerable conjectures many were to quite the contrary effect.
Next, confirmation bias:
But these were only suppositions, which seemed important to the younger men but not to Kutuzov. With his sixty years' experience he knew what value to attach to rumors, knew how apt people who desire anything are to group all news so that it appears to confirm what they desire, and he knew how readily in such cases they omit all that makes for the contrary.
Tolstoy also knew something of statistics and selection bias:
One would have thought that under the almost incredibly wretched conditions the Russian soldiers were in at that time—lacking warm boots and sheepskin coats, without a roof over their heads, in the snow with eighteen degrees of frost, and without even full rations (the commissariat did not always keep up with the troops)—they would have presented a very sad and depressing spectacle.
On the contrary, the army had never under the best material conditions presented a more cheerful and animated aspect. This was because all who began to grow depressed or who lost strength were sifted out of the army day by day. All the physically or morally weak had long since been left behind and only the flower of the army—physically and mentally—remained.
And the value of medicine in those days:
He had what the doctors termed "bilious fever." But despite the fact that the doctors treated him, bled him, and gave him medicines to drink, he recovered.