There are truths, he says, which have attained such an age that they have really outlived themselves. And when a truth becomes as old as this it is on the best way to become a lie. ...Yes, you may believe me or not, but truths are not such long lived Methuselahs as people imagine them to be. A normally constructed truth lives as a rule, let us say, fifteen, sixteen, at the most twenty, years, seldom longer. But such ageing truths become terribly lean and tough. And the majority, having first of all been created by them, later recommends them to humanity as healthy spiritual food. But I can assure you there is not much nourishment in such food. I must speak about this as a doctor. All the truths belonging to the majority are like ancient rancid bacon or like rotten green ham; and from them come all the moral scurvy which is eating itself into the life of the people around us.

The idea of the degeneration of accepted truths cannot be expressed better. Truths that become old become decrepit and unreliable; sometimes they may be kept going artificially for a certain time, but there is no life in them. This explains why reverting to old ideas, when people become disappointed in new ideas, does not help much. Ideas can be too old.

But in other cases old idas may be more pschological than the new. New ideas can be too logical and therefore defective.

We can see many curious examples of the conflict between psychological and logical thinking, which then of necessity becomes defective, in various "intellectual" reforms of old habits and customs. Take, for instance reforms in weights and measures. Weights and measures which have been created through the centuries, and which are different in different countries, appear at the first glance to have taken one or another form by chance and to be too complicated. But in realiy they are always based on one definie principle.

In each separate class of things or material to be measured a different divisor (or muliplier) is used, sometimes very complicated as in the English system of weights -- 16 ounces to a pound, 14 pounds to a stone for comparatively small weights, and for larger weights 28 pounds to a quarter, 112 pounds to a hundredweight, 20 hundredweight to a ton; or, for instance, a simple multiplier like 8 in the Russian measurement of grain which is never repeated in relation to anything else.

This is real psychological method created by life and experience because, thanks to different coefficients in diffrent cases a man making mental calculations involving the measurements of several different materials cannot confuse either objects of different denominations or the measures of different countries (should he have to deal with the measures of different countries) because each order of multiplier itself tells him what is being measured and with what measure. Those who do not like these old complicated systems are the school-teachers, as is well known, the most logical people in the world. Different weights and measures seem to them unnecesarily confusing.

In 1793 the Convention decided to replace the existing French measures by one "natural" measure. After lengthy and complicated "scientific" activity and research such a measure was acknowledged as being one ten-millionth of one fourth part of the earth's meridian, which as called a metre.

There is no direct proof of it, but I am sure that the idea of a "natural" measure and the metric system was born in the minds of teachers of arithmetic, because it is so much easier to divide and multiply everything by ten, having done away with all other divisors and multipliers. But for all ordinary necessities of life the metric system of weights and measures is far less practical than the old systems, and it weakens to a considerable degree a man's ability to make simple mental calculations, which is very marked in countries where the metric system has been adopted. Everyone who has ever been in France remembers the French shopkeepers' pencil and paper on which is often written 5 5/10 (5 over 5 over/10), but there are very few who know that this is one of the conquests of the Great French Revolution.

Exactly the same thing takes place in attempts to change the old orthography. All orthographies must certainly be adapted to new requirements, let us say, once in a hundred years, and this takes place of itself, in a natural way. But violent reforms and the introduction of so-called "phonetic" spelling (only so-called because real phonetic spelling is impossible in any language) generally upsets the entire trend of the normal development of a language, and very soon people begin to write in different ways and then to pronounce in different ways, that is, to adapt pronunciation to the new spelling. This is the result of the application of the logical method to a problem which goes beyond the limits of its possible action.

And it is quite clear why: the process of reading and writing is not a process of reading and writing letters. It is a process of writing words and sentences. Consequently, the more words differ from one another in their form and appearance the easier does the process of reading and writing proceed, and the more they resemble one another (as is inevitable in "phonetic" spelling) the slower and more difficult is the process of reading and writing. It is quite possible that it is easier to teach "phonetic" spelling than the normal spelling, but for the rest of his life the man who has been taught in this way is left with a most unsatisfactory instrument for learning other peoples' ideas and for expressing his own.