Such now is the fruit of education; being for three years, that is to say for all time, divided as it is into three portions, most completely pure and brilliant, being overshadowed by no injurious thing, and having no need whatever of any
 Leviticus xix. 23. 
 
washings or purifications, or any thing else whatever which tends to cleansing.
 "But in the fourth year," says the scripture, "all the fruit of the tree shall be sacred, being praised by the Lord." Leviticus xix. 25. The prophetic books appear often to dignify the number four in many places of the exposition of the law, and most especially in the account of the creation of the universe; for the light which is perceptible by the outward senses, and held in honour, being that which throws the most brilliant light both upon itself and upon other things, and upon its own parents the sun and the moon, and upon the most sacred company of the stars, which by their rising and setting fix the boundaries of night and day, and moreover, of months and years, and which have shown the nature of number, to which, also, the greatest good of the soul is attributed, Moses says was created on the fourth day. And now he honours this day in a remarkable degree, assigning the fruit of the trees to God, in accordance with no other time than with the fourth year after they are planted; for this has a principle in it very consistent with nature and with good morals.
At all events it so happens that the roots of the universe, the elements of which the world is composed, are four—earth, water, air, and fire. Also, that the seasons of the year are equal in number, namely, winter and summer, and those others which are between these two, spring and autumn.