Its original purpose was simply to furnish a resting place for the eye and the mind and so help a little in the grouping of the letters into words, clauses, and sentences, which the mind had hitherto been compelled to do unaided.

It was used at the end of a sentence, at the end of a clause, to indicate abbreviations, to separate crowded words, especially where the sense was ambiguous (ANICEMAN might be either AN ICE MAN or A NICE MAN), or even as an aesthetic ornament between the letters of an inscription.

In early manuscripts the period is usually placed high ([Symbol: High Dot]) instead of low (.).
Sometimes a slanting mark (/) or a double dot (: or ..) was used to indicate the end of an important section of the writing or even of a sentence.
After a time spaces were introduced to show the grouping of the letters and the words.

At first the sentences were separated by spaces, then the long words, and finally all words.

In some languages, as in Italian, there are still combinations of long and short words, such as the combination of the pronoun with the verb, as in _datemi_, give me.
During the manuscript period different schools of copyists and even different individuals used different marks and different systems of pointing.