The line of life governs individual health, and relations with family and relatives. It is the dividing line between family and friends, and the outside world and its influence. In between the two demesnes is the Line of Life.
Though it measures the span and quality of an individual's life, it is not necessarily the final determinant in how long a life is to last for a given individual. Following Cheiro once again, no single evil mark is decisive, thus, when a line of life terminates early, it is imprudent to alarm the subject with words of a doomed life, for there may be other lines that strengthen it greatly.
The line of life also serves to illuminate the quality of family and relatives, as it tracks those in the family who have either helped or hindered the line of life. Though some cheiromancers attribute rays from the Mount of Venus to be indicative of relationships, the author remains skeptical, for though the Venus side of the hand is attributed to romance in some sense, it is not necessarily in the romantic and carnal sense--the Venusians traits in chiromancy are more typically attributed to flourish, enthusiasm, warmth, and vivacity. This compounded with the fact that lines from the mount of Venus typically represent family make these lines unlikely nuptial candidates.
On the neglected hand, the Line of Life is a measure of the quality of life that has been allotted the bearer. On the dominant hand, the Line of Life reveals how the individual has used this life force. If it be shorter, the individual has lived a lifestyle that has generated wear upon them, be it through an unhealthy diet, or even through dangerous or overly-strenuous activities.