No one is presumed to have preferred another’s posterity to his own.

Explanation

The law presumes that a man provides for his own descendants before strangers — in construing wills and grants, preference for one’s own issue is the default assumption.

Where this applies

• A will is interpreted as favoring the testator's own children over strangers.
• Someone claims a grandparent intended to disinherit their own family in favor of outsiders.