An 1860 guide for a gentleman’s conduct in conversations.

One of the first rules for a guide in polite conversation, is to avoid political or religious discussions in general society. Such discussions lead almost invariably to irritating differences of opinion, often to open quarrels, and a coolness of feeling which might have been avoided by dropping the distasteful subject as soon as marked differences of opinion arose. It is but one out of many that can discuss either political or religious differences, with candor and judgment, and yet so far control his language and temper as to avoid either giving or taking offence.

The Gentlemen’s Book of Etiquette and Manual of Politeness, by Cecil B. Hartley

A Kondratieff Wave refers to 40 to 60 years cycles experienced by capitalist economies.

Kondratieff Cycles and long waves of prosperity (Riddhi Sheth Dash)

Economists have identified 5 Kondratieff Waves since the 18th century.

  1. The first resulted from the invention of the steam engine and ran from 1780 to 1830.
  2. The second cycle arose because of the steel industry and the spread of railroads, and ran from 1830 to 1880.
  3. The third cycle resulted from electrification and innovation in the chemical industry, and ran from 1880 to 1930.
  4. The fourth cycle was fueled by autos and petrochemicals, and lasted from 1930 to 1970.
  5. The fifth cycle was based on information technology and began in 1970 and ran through the present, though some economists believe we are at the start of a sixth wave that will be driven by biotechnology and healthcare.

For all his troubles, the Russian economist Nikolai Dmitriyevich Kondratiev was killed by a firing squad in 1938.

[Via Investopedia]