100 YEARS AGO

The question I wish to bring to your notice to-day is an old one: if two events happen simultaneously or one follows the other at a short interval of time, does this give us any reason to suppose that these two events are connected with each other, both being due to the same cause, or one being the cause of the other? Everyone admits that the simple concurrence of events proves nothing, but if the same combination recurs sufficiently often we may reasonably conclude that there is a real connection. The question to be decided in each case is what is “sufficient” and what is “reasonable”. Here we must draw a distinction between experiment and observation. … The cause of the difference lies in the fact that in an experiment we can control to a great extent all the circumstances on which the result depends, and we are generally right in assuming that an experiment which gives a certain result on three successive days will do so always. But even this sometimes depends on the fact that the apparatus is not disturbed, and that the housemaid has not come in to dust the room. Here lies the difference.

From Nature 16 October 1902.

50 YEARS AGO

Our present political systems are likely to be modified. Democracy lacks survival value. The state of parasitism on the community engendered by modern social conditions is impermanent because in the end the parasite destroys its host and then itself perishes: the process is likely to be hastened by the concomitant reduction of the more intelligent, these being now driven to have few or no children. It will be the non-parasitic communities that will survive, and those that multiply most will dominate the earth by sheer numbers. For this reason the author thinks that world agreement to control population could never be attained: an aggressor nation or bloc would never permit their people to restrict their numbers, and other nations that wished to survive would have to follow suit. Government would possibly be by some “hero” who has sufficient sense to adapt himself to a society of dense population. Here intellect will count, but morality may not, since “in a highly competitive world, the sinner has many advantages over the saint”.

From Nature 18 October 1952.