I would have plenty of games in the dark!  This suggestion is more valuable than it seems at first sight.  Men are naturally afraid of the dark; so are some animals. [Footnote:  This terror is very noticeable during great eclipses of the sun.] Only a few men are freed from this burden by knowledge, determination, and courage.  I have seen thinkers, unbelievers, philosophers, exceedingly brave by daylight, tremble like women at the rustling of a leaf in the dark.  This terror is put down to nurses’ tales; this is a mistake; it has a natural cause.  What is this cause?  What makes the deaf suspicious and the lower classes superstitious?  Ignorance of the things about us, and of what is taking place around us. [Footnote:  Another cause has been well explained by a philosopher, often quoted in this work, a philosopher to whose wide views I am very greatly indebted.]

When under special conditions we cannot form a fair idea of distance, when we can only judge things by the size of the angle or rather of the image formed in our eyes, we cannot avoid being deceived as to the size of these objects.  Every one knows by experience how when we are travelling at night we take a bush near at hand for a great tree at a distance, and vice versa.  In the same way, if the objects were of a shape unknown to us, so that we could not tell their size in that way, we should be equally mistaken with regard to it.  If a fly flew quickly past a few inches from our eyes, we should think it was a distant bird; a horse standing still at a distance from us in the midst of open country, in a position somewhat like that of a sheep, would be taken for a large sheep, so long as we did not perceive that it was a horse; but as soon as we recognise what it is, it seems as large as a horse, and we at once correct our former judgment.

Whenever one finds oneself in unknown places at night where we cannot judge of distance, and where we cannot recognise objects by their shape on account of the darkness, we are in constant danger of forming mistaken judgments as to the objects which present themselves to our notice.  Hence that terror, that kind of inward fear experienced by most people on dark nights.  This is foundation for the supposed appearances of spectres, or gigantic and terrible forms which so many people profess to have seen.  They are generally told that they imagined these things, yet they may really have seen them, and it is quite possible they really saw what they say they did see; for it will always be the case that when we can only estimate the size of an object by the angle it forms in the eye, that object will swell and grow as we approach it; and if the spectator thought it several feet high when it was thirty or forty feet away, it will seem very large indeed when it is a few feet off; this must indeed astonish and alarm the spectator until he touches it and perceives what it is, for as soon as he perceives what it is, the object which seemed