Of Recognition by Sight
I am about to appear very inconsistent. In previous sections I have said that all Figures in Flatland present the appearance of a straight line; and it was added or implied, that it is consequently impossible to distinguish by the visual organ between individuals of different classes: yet now I am about to explain to my Spaceland critics how we are able to recognize one another by the sense of sight.
If however the reader will take the trouble to refer to the passage in which Recognition by Feeling is stated to be universal, he will find this qualification—“among the lower classes.” It is only among the higher classes and in our temperate climates that Sight Recognition is practised.
That this power exists in any regions and for any classes is the result of fog; which prevails during the greater part of the year in all parts save the torrid zones. That which is with you in Spaceland an unmixed evil, blotting out the landscape, depressing the spirits, and enfeebling the health, is by us recognized as a blessing scarcely inferior to air itself, and as the nurse of arts and parent of sciences. But let me explain my meaning, without further eulogies on this beneficent element.
If fog were nonexistent, all lines would appear equally and indistinguishably clear; and this is actually the case in those unhappy countries in which the atmosphere is perfectly dry and transparent. But wherever there is a rich supply of fog, objects that are at a distance, say of three feet, are appreciably dimmer than those at a distance of two feet eleven inches; and the result is that by careful and constant experimental observation of comparative dimness and clearness, we are enabled to infer with great exactness the configuration of the object observed.